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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. 0
1, 1, 3, 9, 28, 93, 315, 1091, 3855, 13797, 49929, 182361, 671088, 2485504, 9256395, 34636833, 130150493, 490853403, 1857283155, 7048151355, 26817356775, 102280151421, 390937467284, 1497207322929, 5744387279808, 22076468760335 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Halved bisection of A001037.

LINKS

Table of n, a(n) for n=0..25.

FORMULA

a(n) = A001037(2n+1)/2.

CROSSREFS

Cf. A001037, A059966.

Sequence in context: A105849 A243156 A228449 * A191637 A238978 A081914

Adjacent sequences:  A131200 A131201 A131202 * A131204 A131205 A131206

KEYWORD

nonn

AUTHOR

Max Alekseyev, Sep 27 2007

STATUS

approved

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Last modified January 19 04:17 EST 2020. Contains 331031 sequences. (Running on oeis4.)