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A091982 Nonprimes n such that Mod(n,4) == 1 and denominator(Fibonacci((n-1)/4)/n) = 1. 2
1, 4181, 6721, 13201, 34561, 51841, 64681, 90061, 96049, 97921, 163081, 186961, 197209, 268801, 283361, 302101, 330929, 399001, 489601, 520801, 636641, 655201, 920577, 999941, 1034881, 1072513, 1081649, 1084201, 1106561, 1317121, 1346269, 1392169, 1533601 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..2500

MATHEMATICA

Select[Range[1, 10^6, 4], And[! PrimeQ@ #, Denominator[Fibonacci[(# - 1)/4]/#] == 1] &] (* Michael De Vlieger, May 07 2017 *)

CROSSREFS

For primes see A047272.

Sequence in context: A093372 A212424 A319168 * A238082 A072322 A045728

Adjacent sequences:  A091979 A091980 A091981 * A091983 A091984 A091985

KEYWORD

nonn,easy

AUTHOR

Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 17 2004

EXTENSIONS

a(16)-a(33) from Giovanni Resta, May 06 2017

STATUS

approved

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Last modified November 22 00:32 EST 2019. Contains 329383 sequences. (Running on oeis4.)