A009003: Hypotenuse numbers (squares are sums of 2 nonzero squares).

Consistent, somewhat high-pitched static noise. 

Residue counts:
2   [356496, 364876]
3   [235851, 242764, 242757]
4   [175909, 187189, 180587, 177687]
5   [200000, 130296, 130448, 130356, 130272]
6   [116319, 122657, 120070, 119532, 120107, 122687]
7   [99339, 103675, 103643, 103771, 103594, 103621, 103729]
8   [86653, 93586, 92925, 88819, 89256, 93603, 87662, 88868]
9   [76838, 80848, 80911, 79495, 80969, 81016, 79518, 80947, 80830]
10   [100000, 66157, 64137, 66226, 64090, 100000, 64139, 66311, 64130, 66182]
11   [62572, 65838, 65937, 65859, 65927, 65895, 65876, 65873, 65819, 65825, 65951]
12   [57240, 64649, 60746, 61641, 59345, 64649, 59079, 58008, 59324, 57891, 60762, 58038]

First 100 first differences:
[5, 3, 2, 2, 3, 5, 1, 3, 1, 4, 1, 2, 2, 1, 1, 4, 5, 1, 1, 1, 2, 3, 2, 1, 4, 3, 
 2, 3, 1, 1, 3, 2, 2, 3, 2, 2, 1, 1, 4, 2, 3, 1, 1, 2, 1, 1, 3, 1, 1, 2, 2, 1, 
 1, 2, 1, 2, 1, 2, 5, 5, 1, 1, 3, 3, 2, 1, 2, 1, 1, 3, 2, 1, 1, 2, 1, 4, 1, 4, 
 1, 3, 1, 1, 3, 2, 1, 1, 1, 2, 2, 3, 3, 1, 1, 2, 3, 2, 1, 1, 1, 3]

First 99 second differences:
[-2,-1,0,1,2,-4,2,-2,3,-3,1,0,-1,0,3,1,-4,0,0,1,1,-1,-1,3,-1,-1,1,-2,0,2,-1,0,
 1,-1,0,-1,0,3,-2,1,-2,0,1,-1,0,2,-2,0,1,0,-1,0,1,-1,1,-1,1,3,0,-4,0,2,0,-1,-1,
 1,-1,0,2,-1,-1,0,1,-1,3,-3,3,-3,2,-2,0,2,-1,-1,0,0,1,0,1,0,-2,0,1,1,-1,-1,0,0,2]

One frequency stands out at 8820Hz which corresponds to 44100/5.


--David Oh