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A323353 Numbers k such that A015525(k) is prime. 1
2, 3, 7, 11, 13, 73, 401, 421, 677, 3673, 4903, 13147, 24547 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..13.

PROG

(PARI) print1(2, ", "); anm2=1; anm1=3; for(n=3, 1000, an=3*anm1+8*anm2; anm2=anm1; anm1=an; if(isprime(an), print1(n, ", ")))

(Perl) use ntheory ":all"; sub isok { is_prob_prime(lucasu(3, -8, $_[0])) }; for (1..700) { print "$_\n" if isok($_) }; # Daniel Suteu, Jan 12 2019

CROSSREFS

Cf. A015525, A323354.

Sequence in context: A291657 A113244 A040152 * A188529 A174060 A285278

Adjacent sequences:  A323350 A323351 A323352 * A323354 A323355 A323356

KEYWORD

nonn,more,hard

AUTHOR

Hugo Pfoertner, Jan 12 2019

EXTENSIONS

a(13) from Daniel Suteu, Jan 12 2019

STATUS

approved

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Last modified December 6 06:14 EST 2021. Contains 349563 sequences. (Running on oeis4.)