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A205781 Least positive integer j such that n divides C(k)-C(j), where k, as in A205780, is the least number for which there is such a j, and C=A007598 (squared Fibonacci numbers).

%I A205781 #6 Dec 04 2016 19:46:26
%S A205781 1,1,1,1,2,1,2,1,1,2,3,1,4,1,2,3,6,4,2,2,2,1,2,1,4,4,3,1,5,2,3,3,2,6,
%T A205781 5,4,3,7,4,3,8,1,3,1,1,3,6,4,3,4,6,4,2,3,3,1,2,3,3,2,12,4,1,2,7,1,2,6,
%U A205781 10,6,2,4,2,16,4,7,1,5,4,3,5,6,11,1,7,3,4,1,8,1,5,3,4,4,3,2,5
%N A205781 Least positive integer j such that n divides C(k)-C(j), where k, as in A205780, is the least number for which there is such a j, and C=A007598 (squared Fibonacci numbers).
%C A205781 For a guide to related sequences, see A204892.
%e A205781 1 divides C(2)-C(1) -> k=2, j=1
%e A205781 2 divides C(3)-C(1) -> k=3, j=1
%e A205781 3 divides C(2)-C(1) -> k=2, j=1
%e A205781 4 divides C(3)-C(1) -> k=3, j=1
%e A205781 5 divides C(3)-C(2) -> k=3, j=2
%t A205781 s = Table[(Fibonacci[n + 1])^2, {n, 1, 120}];
%t A205781 lk = Table[
%t A205781   NestWhile[# + 1 &, 1,
%t A205781    Min[Table[Mod[s[[#]] - s[[j]], z], {j, 1, # - 1}]] =!= 0 &], {z, 1,
%t A205781     Length[s]}]
%t A205781 Table[NestWhile[# + 1 &, 1,
%t A205781   Mod[s[[lk[[j]]]] - s[[#]], j] =!= 0 &], {j, 1, Length[lk]}]
%t A205781 (* _Peter J. C. Moses_, Jan 27 2012 *)
%Y A205781 Cf. A204892, A007598.
%K A205781 nonn
%O A205781 1,5
%A A205781 _Clark Kimberling_, Feb 01 2012