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A122869 Primes p that divide Lucas((p-1)/2), where Lucas is A000032. 4
11, 19, 31, 59, 71, 79, 131, 139, 151, 179, 191, 199, 211, 239, 251, 271, 311, 331, 359, 379, 419, 431, 439, 479, 491, 499, 571, 599, 619, 631, 659, 691, 719, 739, 751, 811, 839, 859, 911, 919, 971, 991, 1019, 1031, 1039, 1051, 1091, 1151, 1171, 1231, 1259 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Lucas numbers A000032(n) = Fibonacci(n-1) + Fibonacci(n+1) = A000045(n-1) + A000045(n+1).

Subsequence of A002145, A040105, A064739, A003626, A076518, and A040147.

Final digit of a(n) is 1 or 9.

A002145 is the union of this sequence and A122870, Primes p that divide Lucas((p+1)/2).

Conjecture: This sequence is just the primes congruent to 11 or 19 mod 20. - Charles R Greathouse IV, May 25 2011

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Eric Weisstein's World of Mathematics, Lucas Number.

Eric Weisstein's World of Mathematics, Gaussian Prime.

MATHEMATICA

Select[Prime[Range[1000]], IntegerQ[(Fibonacci[(#1-1)/2-1]+Fibonacci[(#1-1)/2+1])/#1]&]

CROSSREFS

Cf. A000032, A000045, A122870, A002145, A040105, A053032, A064739, A003626, A076518.

Sequence in context: A155555 A152091 A272550 * A106535 A178150 A214784

Adjacent sequences:  A122866 A122867 A122868 * A122870 A122871 A122872

KEYWORD

nonn

AUTHOR

Alexander Adamchuk, Sep 16 2006

STATUS

approved

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Last modified June 26 20:37 EDT 2019. Contains 324380 sequences. (Running on oeis4.)