A025299 Numbers that are the sum of 2 nonzero squares in 8 or more ways.

27625, 32045, 40885, 45305, 47125, 55250, 58565, 60125, 61625, 64090, 66625, 67405, 69745, 71825, 77285, 78625, 80665, 81770, 86125, 87125, 90610, 91205, 93925, 94250, 98345, 98605, 99125, 99905, 101065, 107185, 110500, 111605, 112625, 114985

Offset

1,1

Links

David A. Corneth, Table of n, a(n) for n = 1..10000 (first 98 terms from Robert Price)

Index entries for sequences related to sums of squares

Example

27625 is in the sequence via 20^2 + 165^2 = 27^2 + 164^2 = 45^2 + 160^2 = 60^2 + 155^2 = 83^2 + 144^2 = 88^2 + 141^2 = 101^2 + 132^2 = 115^2 + 120^2. - David A. Corneth, Jun 01 2025

Mathematica

nn = 114985; t = Table[0, {nn}]; lim = Floor[Sqrt[nn - 1]]; Do[num = i^2 + j^2; If[num <= nn, t[[num]]++], {i, lim}, {j, i}]; Flatten[Position[t, _?(# >= 8 &)]] (* T. D. Noe, Apr 07 2011 *)

Prog

(PARI) upto(n) = {my(v = vector(n)); for(i = 1, sqrtint(n), i2 = i^2; for(j = i, sqrtint(n - i^2), v[i2 + j^2]++)); select(x->x >= 8, v, 1)} \\ David A. Corneth, Jun 01 2025

Crossrefs

Cf. A025291, A025298, A025300, A025336.

Sequence in context: A366491 A025298 A025317 * A025318 A025291 A025309

Adjacent sequences: A025296 A025297 A025298 * A025300 A025301 A025302

Keyword

nonn

Author

David W. Wilson

Status

approved