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Composite numbers n such that primitive part of Lucas(n) (see A061447) is prime.
6

%I #18 Apr 03 2023 10:36:10

%S 9,10,14,15,16,20,21,26,27,30,33,36,38,49,56,62,66,68,70,72,76,78,80,

%T 86,90,91,110,117,120,121,136,140,144,164,168,172,178,202,207,220,261,

%U 284,328,354,357,420,423,458,459,468,480,504,513,530,586,606

%N Composite numbers n such that primitive part of Lucas(n) (see A061447) is prime.

%H David Broadhurst, <a href="/A061445/b061445.txt">Table of n, a(n) for n = 1..258 yielding primes or probable primes</a>

%H J. Brillhart, P. L. Montgomery and R. D. Silverman, <a href="https://doi.org/10.1090/S0025-5718-1988-0917832-6">Tables of Fibonacci and Lucas factorizations</a>, Math. Comp. 50 (1988), 251-260, S1-S15. Math. Rev. 89h:11002.

%H C. K. Caldwell, <a href="https://t5k.org/top20/page.php?id=21">Lucas Aurifeuillian primitive part</a>

%e 16 is a term because A061447(16)=2207 is a prime. - _Sean A. Irvine_, Feb 15 2023

%Y Cf. A061446, A061447, A061254, A061442, A061443.

%K nonn

%O 1,1

%A _David Broadhurst_, Jun 10 2001

%E Definition corrected by _T. D. Noe_, Dec 14 2006

%E Missing a(5)=16 inserted by _Sean A. Irvine_, Feb 15 2023