A025319 Numbers that are the sum of 2 distinct nonzero squares in 9 or more ways.

71825, 93925, 122525, 138125, 143650, 156325, 160225, 173225, 187850, 204425, 209525, 223925, 226525, 235625, 244205, 245050, 257725, 267325, 273325, 276250, 287300, 292825, 296225, 300625, 308125, 308425, 312650, 320450, 333125, 337025

Offset

1,1

Comments

Subsequence of A025300. But sequences A025319 and A025300 are different. 2*5^16 = 305175781250 = 36425^2 + 551225^2 = 78125^2 + 546875^2 = 119375^2 + 539375^2 = 189311^2 + 518977^2 = 228125^2 + 503125^2 = 265625^2 + 484375^2 = 301595^2 + 462835^2 = 359875^2 + 419125^2 = 390625^2 + 390625^2 (not distinct squares) is not in A025319. - Vaclav Kotesovec, Feb 27 2016

Numbers in A025300 but not in A025319 are exactly those numbers of the form 2*p_1^(2*a_1)*p_2^(2*a_2)*...*p_m^(2*a_m)*q^16 where p_i are primes of the form 4k+3 and q is a prime of the form 4k+1. Thus 2*5^16 is the smallest term in A025300 that is not in A025319. - Chai Wah Wu, Feb 27 2016

Links

Chai Wah Wu, Table of n, a(n) for n = 1..10000

Index entries for sequences related to sums of squares

Mathematica

nn = 337025; t = Table[0, {nn}]; lim = Floor[Sqrt[nn - 1]]; Do[num = i^2 + j^2; If[num <= nn, t[[num]]++], {i, lim}, {j, i - 1}]; Flatten[Position[t, _?(# >= 9 &)]] (* T. D. Noe, Apr 07 2011 *)

Crossrefs

Sequence in context: A114661 A119397 A025300 * A097245 A025292 A025310

Adjacent sequences: A025316 A025317 A025318 * A025320 A025321 A025322

Keyword

nonn

Author

David W. Wilson

Status

approved