cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A133246 Odd numbers n with property that no odd Fibonacci number is divisible by n.

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%I A133246 #7 Jan 01 2019 20:14:44
%S A133246 9,17,19,23,27,31,45,51,53,57,61,63,69,79,81,83,85,93,95,99,107,109,
%T A133246 115,117,119,133,135,137,153,155,159,161,167,171,173,181,183,187,189,
%U A133246 197,207,209,211,217,221,225,227,229,237,241,243,247,249,253,255,257,261
%N A133246 Odd numbers n with property that no odd Fibonacci number is divisible by n.
%C A133246 The Mathematica coding uses the fact that the Pisano period - the period with which a Fibonacci sequence (mod n) repeats itself is not more than 6n and the fact that the Fibonacci sequence starts with 0.
%H A133246 Tanya Khovanova, <a href="https://arxiv.org/abs/0712.3509">9 Divides no Odd Fibonacci</a>, arXiv:0712.3509 [math.CO], 2007.
%t A133246 Transpose[ Select[Table[{k, Select[Table[{n, Mod[Fibonacci[n], k]}, {n, 6k + 1}], Mod[ #[[1]], 3] != 0 && #[[2]] == 0 &]}, {k, 1, 351, 2}], #[[2]] == {} &]][[1]]
%Y A133246 Cf. A133247.
%K A133246 nonn
%O A133246 1,1
%A A133246 _Tanya Khovanova_, Oct 14 2007, Oct 17 2007