A122721 - OEIS

A122721

Numbers n such that abs(7^n - 2^11) is prime.

2, 4, 5, 6, 9, 21, 41, 52, 58, 118, 130, 585, 614, 744, 881, 941, 966, 1280, 1658, 4985

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OFFSET

1,1

LINKS

EXAMPLE

For x = 2 abs(7^2-2^11) = 1999 which is prime. So 2 is the first entry.

PROG

(PARI) g(n) = for(x=1, n, y=abs(7^x-2^11); if(ispseudoprime(y), print1(x", ")))

CROSSREFS

KEYWORD

easy,nonn

AUTHOR

STATUS

approved