

A303737


Numbers k such that (2*k)! + k!  1 is prime.


1




OFFSET

1,2


COMMENTS

a(9) > 10000.  Giovanni Resta, Jun 07 2018


LINKS

Table of n, a(n) for n=1..8.


EXAMPLE

1 is a term because (2*1)! + 1!  1 = 2 which is a prime.
4 is a term because (2*4)! + 4!  1 = 40343 which is a prime.


MAPLE

select(k>isprime(factorial(2*k)+factorial(k)1), [$1..1000]);


PROG

(PARI) isok(k) = isprime((2*k)! + k!  1); \\ Michel Marcus, May 28 2018


CROSSREFS

Cf. A242487, A300947, A303738 (corresponding primes).
Sequence in context: A081528 A056147 A181857 * A180805 A120656 A256431
Adjacent sequences: A303734 A303735 A303736 * A303738 A303739 A303740


KEYWORD

nonn,more


AUTHOR

Muniru A Asiru, May 27 2018


EXTENSIONS

a(8) from Giovanni Resta, Jun 07 2018


STATUS

approved



