OIES id | description | sound player | creator | |

A000069 | odious numbers: numbers with an odd number of 1's in their binary expansion | download | Emily Flanagan | |

A000124 | quadratic sequence n(n+1)/2 + 1 | download | Emily Flanagan | |

A000566 | heptagonal numbers (or 7-gonal numbers): n(5n-3)/2 | download | Emily Flanagan | |

A005891 | centered pentagonal numbers: (5n^2+5n+2)/2 | download | Emily Flanagan, Jesse Rivera | |

A005901 | quadratic sequence 10n^2 + 2 | download | Emily Flanagan | |

A005905 | quadratic sequence 14n^2 + 2 | download | Emily Flanagan | |

A005914 | quadratic sequence 12n^2 + 2 | download | Emily Flanagan | |

A006446 | numbers n such that floor(sqrt(n)) divides n | download | Emily Flanagan | |

A010003 | quadratic sequence 11n^2 + 2 | download | Emily Flanagan | |

A010004 | quadratic sequence 13n^2 + 2 | download | Emily Flanagan | |

A023254 | numbers that remain prime through 2 iterations of the function f(x) = 5x + 6 | download | Emily Flanagan | |

A023255 | numbers that remain prime through 2 iterations of the function f(x) = 5x + 8 | download | Emily Flanagan | |

A023256 | numbers that remain prime through 2 iterations of the function f(x) = 6x + 1 | download | Emily Flanagan | |

A023257 | numbers that remain prime through 2 iterations of the function f(x) = 6x + 5 | download | Emily Flanagan | |

A023258 | numbers that remain prime through 2 iterations of the function f(x) = 6x + 7 | download | Emily Flanagan | |

A206399 | quadratic sequence 41n^2 + 2 | download | Emily Flanagan | |

A259486 | 3n^2 - 3n + 1 + 6 floor((n-1)(n-2)/6) | download | Emily Flanagan | |

A268037 | numbers n such that the number of divisors of n+2 divides n and the number of divisors of n divides n+2 | download | Emily Flanagan | |

A000062 | floor(n/(e-2)) | download | Jesse Rivera | |

A001951 | floor(n sqrt(2)) | download | Jesse Rivera | |

A002473 | numbers whose prime divisors are all <= 7 | download | Jesse Rivera | |

A003136 | numbers of the form x^2 + xy + y^2 | download | Jesse Rivera | |

A006218 | sum of the number of divisors of k, k=1,...,n | download | Jesse Rivera | |

A011257 | geometric mean of phi(n) and sigma(n) is an integer | download | Jesse Rivera | |

A022838 | floor( n sqrt(3)) | download | Jesse Rivera | |

A022839 | floor(n sqrt(5)) | download | Jesse Rivera | |

A022843 | floor(n e) | download | Jesse Rivera | |

A022844 | floor(n pi) | download | Jesse Rivera | |

A030513 | numbers with four divisors | download | Jesse Rivera | |

A030626 | numbers with eight divisors | download | Jesse Rivera | |

A036844 | numbers divisible by the sum of their prime factors | download | Jesse Rivera | |

A038152 | floor(n e^pi) | download | Jesse Rivera | |

A038153 | floor(n pi^e) | download | Jesse Rivera | |

A051913 | numbers n such that phi(n)/phi(phi(n)) = 3 | download | Jesse Rivera | |

A080683 | numbers whose prime divisors are all <= 23 | download | Jesse Rivera | |

A165350 | primes p such that floor((p^2-1)/4)+p is not prime | download | Jesse Rivera | |

A190751 | n+[ns/r]+[nt/r]+[nu/r]+[nv/r]+[nw/r], where r=sinh(x), s=cosh(x), t=tanh(x), u=csch(x), v=sech(x), w=coth(x), where x=pi/2 | download | Jesse Rivera | |

A252895 | numbers with an odd number of square divisors | download | Jesse Rivera | |

A274685 | odd numbers n such that sigma(n) is divisible by 5 | download | Jesse Rivera | |

A277052 | n+floor(n/(2/sqrt(Pi)-1)) | download | Jesse Rivera | |

A250046 | numbers n such that m = floor(n/7) is coprime to n and, if nonzero, m is also a term of the sequence | download | Penny Espinoza | |

A250046 | numbers n such that m = floor(n/7) is coprime to n and, if nonzero, m is also a term of the sequence (longer version) | download | Penny Espinoza | |

A250048 | numbers n such that m = floor(n/6) is coprime to n and, if nonzero, m is also a term of the sequence | download | Penny Espinoza | |

A250050 | numbers n such that m = floor(n/5) is coprime to n and, if nonzero, m is also a term of the sequence | download | Penny Espinoza | |

A250036 | numbers n such that m = floor(n/4) is coprime to n and, if nonzero, m is also a term of the sequence | download | Penny Espinoza | |

A250038 | numbers n such that m = floor(n/16) is coprime to n and, if nonzero, m is also a term of the sequence | download | Penny Espinoza | |

A250040 | numbers n such that m = floor(n/10) is coprime to n and, if nonzero, m is also a term of the sequence | download | Penny Espinoza | |

A250042 | numbers n such that m = floor(n/9) is coprime to n and, if nonzero, m is also a term of the sequence | download | Penny Espinoza | |

A250044 | numbers n such that m = floor(n/8) is coprime to n and, if nonzero, m is also a term of the sequence | download | Penny Espinoza | |

A161165 | the n-th twin prime plus the n-th isolated prime | download | Penny Espinoza | |

A166251 | isolated primes: primes p such that there is no other prime in the interval [2 prevprime(p/2), 2 nextprime(p/2)] | download | Penny Espinoza | |

A167706 | single or isolated numbers: the union of single (or isolated or non-twin) primes and single (or isolated or average of twin prime pairs) nonprimes | download | Penny Espinoza | |

A167771 | Twice-isolated primes: primes p such that neither p+-2 nor p+-4 is prime | download | Penny Espinoza | |

A065049 | Odd primes of incorrect parity: number of 1's in the binary representation of n (mod 2) equals 1 - (n mod 3) (mod 2). Also called isolated primes. | download | Penny Espinoza | |

A147778 | positive integers of the form u*v*(u^2-v^2) where u,v are co-prime integers | download | Penny Espinoza | |

A153777 | minimal sequence S such that 1 is in S and if x is in S, then 5x-1 and 5x+1 are in S | download | Penny Espinoza | |

A153777 | minimal sequence S such that 1 is in S and if x is in S, then 5x-1 and 5x+1 are in S (10 minute version: silence after 4:36) | download | Penny Espinoza | |

A003586 | 3-smooth numbers: numbers of the form 2^i 3^j with i, j >= 0 | download | Penny Espinoza | |

A033845 | numbers of the form 2^i 3^j, with i,j >= 1 | download | Penny Espinoza | |

A052160 | isolated prime difference equals 6: d(n)=p(n+1)-p(n)=6 but d(n+1) and d(n-1) differ from 6 | download | Penny Espinoza | |

A001097 | twin primes | download | Penny Espinoza | |

A007510 | single, isolated or non-twin primes: primes p such that neither p-2 nor p+2 is prime | download | Penny Espinoza | |

A181732 | numbers n such that 90n + 1 is prime | download | Penny Espinoza | |

A196000 | numbers n such that 90n + 19 is prime | download | Penny Espinoza | |

A198382 | numbers n such that 90n + 37 is prime | download | Penny Espinoza | |

A201734 | numbers n such that 90n + 47 is prime | download | Penny Espinoza | |

A195993 | numbers n such that 90n + 73 is prime | download | Penny Espinoza | |

A196007 | numbers n such that 90n + 83 is prime | download | Penny Espinoza | |

A006450 | prime-indexed primes: primes with prime subscripts | download | Penny Espinoza | |

A066643 | floor(pi n^2) | download | Penny Espinoza | |

A018900 | Sum of digits in base 2 is 2 | download | Penny Espinoza | |

A226636 | Sum of digits in base 3 is 3 | download | Penny Espinoza | |

A226969 | Sum of digits in base 4 is 4 | download | Penny Espinoza | |

A227062 | Sum of digits in base 5 is 5 | download | Penny Espinoza | |

A227080 | Sum of digits in base 6 is 6 | download | Penny Espinoza | |

A227092 | Sum of digits in base 7 is 7 | download | Penny Espinoza | |

A227095 | Sum of digits in base 8 is 8 | download | Penny Espinoza | |

A227238 | Sum of digits in base 9 is 9 | download | Penny Espinoza | |

A052224 | Sum of digits in base 10 is 10 | download | Penny Espinoza | |

Sum of digits in base 55 equals 55 | download | Penny Espinoza |