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 A274591 Least number k such that k-1, k, k+1 are the sum of two nonzero squares in exactly n ways. 0
 73, 22049, 90707201, 4359889 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Corresponding triples are (72, 73, 74), (22048, 22049, 22050), (90707200, 90707201, 90707202), (4359888, 4359889, 4359890) for first four terms. a(6) = 1428907401, a(8) = 2305281745. No more terms < 2*10^11. - Lars Blomberg, Jun 01 2018 a(5) > 10^15, if it exists. - Giovanni Resta, Jun 05 2018 LINKS EXAMPLE a(2) = 22049 because 22048 = 12^2 + 148^2 = 68^2 + 132^2, 22049 = 32^2 + 145^2 = 40^2 + 143^2, 22050 = 21^2 + 147^2 = 105^2 + 105^2. CROSSREFS Cf. A064716, A274548. Sequence in context: A210382 A091757 A070531 * A232293 A232366 A183490 Adjacent sequences:  A274588 A274589 A274590 * A274592 A274593 A274594 KEYWORD nonn,hard,more AUTHOR Altug Alkan, Jun 29 2016 STATUS approved

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Last modified January 22 11:21 EST 2021. Contains 340362 sequences. (Running on oeis4.)