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A358878
Numbers k such that k! + (k!/2) - 1 is prime.
4
2, 5, 7, 15, 20, 47, 84, 138, 169, 257, 263, 431, 559, 2939, 4403, 4870, 5273
OFFSET
1,1
COMMENTS
Numbers k such that A070960(k) - 1 is prime.
No more terms < 10000. - Vaclav Kotesovec, Dec 12 2022
PROG
(PARI) is(k) = isprime(k!+(k!/2)-1);
CROSSREFS
Sequence in context: A076720 A245921 A215513 * A306956 A337655 A366175
KEYWORD
nonn,more
AUTHOR
Arsen Vardanyan, Dec 04 2022
EXTENSIONS
a(14)-a(17) from Vaclav Kotesovec, Dec 07 2022
STATUS
approved