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A238240 Positive integers n such that x^2 - 20xy + y^2 + n = 0 has integer solutions. 2
18, 63, 72, 74, 83, 90, 99, 107, 162, 171, 227, 252, 288, 296, 315, 332, 347, 359, 360, 362, 387, 396, 407, 428, 450, 491, 495, 567, 626, 648, 666, 684, 711, 743, 747, 794, 810, 827, 842, 855, 866, 882, 887, 891, 908, 954, 963, 1008, 1031, 1143, 1152, 1163 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..52.

EXAMPLE

63 is in the sequence because x^2 - 20xy + y^2 + 63 = 0 has integer solutions, for example (x, y) = (1, 16).

CROSSREFS

Cf. A075839 (n = 18), A221763 (n = 63), A198947 (n = 90), A001085 (n = 99).

Cf. A031363, A084917, A237351, A237599, A237606, A237609, A237610, A236330, A236331.

Sequence in context: A090073 A327089 A016728 * A232385 A275155 A259634

Adjacent sequences:  A238237 A238238 A238239 * A238241 A238242 A238243

KEYWORD

nonn

AUTHOR

Colin Barker, Feb 20 2014

STATUS

approved

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Last modified January 22 07:39 EST 2020. Contains 331139 sequences. (Running on oeis4.)