cp's OEIS Frontend

A131203 Number of cycles of length n under the mapping x -> x^2-2 modulo Fermat prime 2^(2^m)+1, where m is any fixed integer such that n divides 2^m-1.

%I A131203 #18 Jun 22 2024 16:15:53
%S A131203 1,1,3,9,28,93,315,1091,3855,13797,49929,182361,671088,2485504,
%T A131203 9256395,34636833,130150493,490853403,1857283155,7048151355,
%U A131203 26817356775,102280151421,390937467284,1497207322929,5744387279808,22076468760335
%N A131203 Number of cycles of length n under the mapping x -> x^2-2 modulo Fermat prime 2^(2^m)+1, where m is any fixed integer such that n divides 2^m-1.
%C A131203 Halved bisection of A001037.
%C A131203 Bisection of A000048. Number of 2m bead balanced binary necklaces of fundamental period 4n+2 that are equivalent to their complements, where m is any multiple of 2n+1. - _Aaron Meyerowitz_, Jun 01 2024
%F A131203 a(n) = A001037(2n+1)/2.
%Y A131203 Cf. A000048, A001037, A059966.
%K A131203 nonn
%O A131203 0,3
%A A131203 _Max Alekseyev_, Sep 27 2007