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A025305 Numbers that are the sum of 2 distinct nonzero squares in exactly 4 ways. 3

%I #17 Dec 08 2013 06:30:06

%S 1105,1625,1885,2125,2210,2405,2465,2665,3145,3250,3445,3485,3625,

%T 3770,3965,4225,4250,4420,4505,4625,4745,4810,4930,5125,5185,5330,

%U 5365,5785,5945,6205,6290,6305,6409,6500,6565,6625,6890,6970,7085,7225,7250,7345

%N Numbers that are the sum of 2 distinct nonzero squares in exactly 4 ways.

%C 8450 is the first term in here but not in A025287 [R. Chandler, seqfan list, May 28 2008] [From _R. J. Mathar_, Nov 30 2008]

%H Donovan Johnson, <a href="/A025305/b025305.txt">Table of n, a(n) for n = 1..1000</a>

%H <a href="/index/Su#ssq">Index entries for sequences related to sums of squares</a>

%t nn = 8450; 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, 4]] (* _T. D. Noe_, Apr 07 2011 *)

%K nonn

%O 1,1

%A _David W. Wilson_

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Last modified April 19 18:05 EDT 2024. Contains 371798 sequences. (Running on oeis4.)