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A025301 Numbers that are the sum of 2 nonzero squares in 10 or more ways. 2
138125, 160225, 204425, 226525, 235625, 276250, 292825, 300625, 308125, 320450, 333125, 337025, 348725, 359125, 386425, 393125, 403325, 408850, 416585, 430625, 435625, 453050, 456025, 469625, 471250, 491725, 493025, 495625, 499525, 505325 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Sequences A025320 and A025301 are different. 2*5^18 = 7629394531250 = 182125^2 + 2756125^2 = 390625^2 + 2734375^2 = 596875^2 + 2696875^2 = 799687^2 + 2643841^2 = 946555^2 + 2594885^2 = 1140625^2 + 2515625^2 = 1328125^2 + 2421875^2 = 1507975^2 + 2314175^2 = 1799375^2 + 2095625^2 = 1953125^2 + 1953125^2 (not distinct squares) is not in A025320. - Vaclav Kotesovec, Feb 27 2016

Numbers in A025301 but not in A025320 are exactly those numbers of the form 2*p_1^(2*a_1)*p_2^(2*a_2)*...*p_m^(2*a_m)*q^18 where p_i are primes of the form 4k+3 and q is a prime of the form 4k+1.  Thus 2*5^18 is the smallest term in A025301 that is not in A025320. - 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 = 505325; 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, _?(# >= 10 &)]] (* T. D. Noe, Apr 07 2011 *)

CROSSREFS

Sequence in context: A110598 A069336 A296341 * A025320 A025293 A025311

Adjacent sequences:  A025298 A025299 A025300 * A025302 A025303 A025304

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified November 19 03:27 EST 2019. Contains 329310 sequences. (Running on oeis4.)