A171247 Numbers k such that 1 + 20^k + 200^k is prime.

0, 19, 59, 291, 327, 3951, 18163

Offset

1,2

Comments

No more terms up to k = 6900.

Links

Table of n, a(n) for n=1..7.

Prog

(PARI) is(n)=ispseudoprime(1+20^n+200^n) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A236462 A139981 A235705 * A270818 A206426 A211145

Adjacent sequences: A171244 A171245 A171246 * A171248 A171249 A171250

Keyword

nonn,more

Author

Jason Earls, Dec 06 2009

Extensions

Offset changed by Andrew Howroyd, Sep 18 2024

a(7) from Michael S. Branicky, Sep 21 2024

Status

approved