

A227446


Numbers k such that 7*2^(2*k)5*2^kn+1 is prime.


0




OFFSET

1,3


COMMENTS

a(9) > 10000.  Jinyuan Wang, Feb 12 2019


LINKS

Table of n, a(n) for n=1..8.
Eric L. F. Roettger, A Cubic Extension of the Lucas Functions, Ph. D. Dissertation, Dept. Math. and Statistics, Univ. Calgary, 2009 (see page 196).


MAPLE

select(isprime, [seq(7*2^(2*n)5*2^n+1, n=0..1000)]); # Jinyuan Wang, Feb 12 2019


MATHEMATICA

Select[Range[0, 3000], PrimeQ[7 2^(2 #)  5 2^# + 1]&]


PROG

(PARI) for(n=0, 10^6, if(ispseudoprime(7*2^(2*n)5*2^n+1), print1(n, ", "))); \\ Joerg Arndt, Jul 14 2013


CROSSREFS

Cf. A058593.
Sequence in context: A167910 A147042 A018492 * A059020 A290720 A289654
Adjacent sequences: A227443 A227444 A227445 * A227447 A227448 A227449


KEYWORD

nonn,more


AUTHOR

Vincenzo Librandi, Jul 14 2013


EXTENSIONS

a(8) from Jinyuan Wang, Feb 12 2019


STATUS

approved



