A076209 Numbers n such that (n!!+(n+1)!!-1)/2 is prime.

2, 3, 4, 5, 28, 35, 61, 75, 218, 267, 395, 844, 1509, 2122, 4157

Offset

1,1

Links

Table of n, a(n) for n=1..15.

Crossrefs

Cf. A006882 (double factorials), A076208, A076210, A076211.

Sequence in context: A115337 A114333 A265098 * A037399 A220891 A220890

Adjacent sequences: A076206 A076207 A076208 * A076210 A076211 A076212

Keyword

nonn

Author

Zak Seidov, Nov 02 2002

Extensions

More terms (checked n<5000) from Hugo Pfoertner, Jun 22 2003

Status

approved