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A307843 Divisors of Fermat numbers. 0
1, 3, 5, 17, 257, 641, 65537, 114689, 274177, 319489, 974849, 2424833, 6700417, 13631489, 26017793, 45592577, 63766529, 167772161, 825753601, 1214251009, 4294967297, 6487031809, 70525124609, 190274191361, 311453532161, 646730219521, 2710954639361 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Has both A000215 and A023394 as subsequences. Outside these are 1 and the composite proper divisors of Fermat numbers, namely 311453532161, 2983954661377, 7313319444481, ...

LINKS

Table of n, a(n) for n=1..27.

EXAMPLE

311453532161 is included because it divides 2^(2^11) + 1. It is not included in A023394 because it is composite.

CROSSREFS

Cf. A023394, A000215, A094358.

Sequence in context: A273870 A272060 A058910 * A023394 A176689 A256510

Adjacent sequences:  A307840 A307841 A307842 * A307844 A307845 A307846

KEYWORD

nonn

AUTHOR

Jeppe Stig Nielsen, Jul 24 2019

STATUS

approved

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Last modified November 12 17:06 EST 2019. Contains 329058 sequences. (Running on oeis4.)