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 A219114 Integers n such that n^2 is the difference of two Fibonacci numbers. 5
 0, 1, 2, 4, 9, 12, 15, 24 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Numbers n such that n^2 is in A007298. No other terms below 10^10000. - Manfred Scheucher, Jun 12 2015 LINKS Manfred Scheucher, Sage Script EXAMPLE The only known square differences of Fibonacci numbers are: 0^2 = F(2)-F(1) = F(k)-F(k) for any k, 1^2 = F(1)-F(0) = F(2)-F(0) = F(3)-F(1) = F(3)-F(2) = F(4)-F(3), 2^2 = F(5)-F(1) = F(5)-F(2), 4^2 = F(8)-F(5), 9^2 = F(11)-F(6), 12^2 = F(12)-F(0) = F(13)-F(11) = F(14)-F(13), 15^2 = F(13)-F(6), 24^2 = F(15)-F(9). MATHEMATICA t = Union[Flatten[Table[Fibonacci[n] - Fibonacci[i], {n, 100}, {i, n}]]]; t2 = Select[t, IntegerQ[Sqrt[#]] &]; Sqrt[t2] (* T. D. Noe, Feb 12 2013 *) CROSSREFS Cf. A000045 (Fibonacci numbers). Cf. A007298 (differences of Fibonacci numbers). Sequence in context: A096186 A175041 A298823 * A182859 A088901 A283147 Adjacent sequences:  A219111 A219112 A219113 * A219115 A219116 A219117 KEYWORD nonn,hard,more AUTHOR Max Alekseyev, Nov 12 2012 STATUS approved

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Last modified January 20 11:01 EST 2020. Contains 331083 sequences. (Running on oeis4.)