A096783 Numbers n such that n, n+1, n+2, n+3, n+4 are all of the form x^2+2*y^2 for nonnegative x, y.
0, 96, 800, 2400, 3200, 3648, 4096, 4800, 6272, 7296, 9600, 18272, 19648, 20000, 20672, 23648, 28224, 28800, 29472, 31424, 34848, 36896, 37472, 43072, 48672, 50272, 51200, 53600, 53824, 55072, 57696, 59648, 62848, 64800, 66048, 69824
Offset: 1
Keywords
Examples
96=8^2+2*4^2, 97=5^2+2*6^2, 98 = 0^2+2*7^2,99=9^2+2*3^2=7^2+2*5^2,100=10^2+2*0^2
Programs
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Mathematica
f[n_] := f[n_] = Block[{y = 0}, While[x = Sqrt[n - 2y^2]; !IntegerQ[x] && x >= 0, y++ ]; If[x \[Element] Reals, 1, 0]]; Select[ Range[0, 76895], f[ # ] == f[ # + 1] == f[ # + 2] == f[ # + 3] == f[ # + 4] == 1 &] (* Robert G. Wilson v, Aug 20 2004 *)
Extensions
More terms from Robert G. Wilson v, Aug 20 2004