A290047 Primes in A290046.

2, 45181, 6290021506693847759, 25266964023001914822246560759, 10384129888710330539039375199241

Offset

1,1

Comments

For n < 26, A290046(n) are primes when n = {1, 4, 11, 15, 16}.

For n >= 26, 41|A290046(n). Therefore there are only 5 terms in this sequence.

Links

Table of n, a(n) for n=1..5.

Example

45181 = |0!! - 3!! + 6!! - 9!! + 12!!| is prime.

Mathematica

Select[#, PrimeQ] &@ Table[Abs@ Sum[(-1)^k*(3 k)!!, {k, 0, n}], {n, 0, 30}] (* Michael De Vlieger, Jul 19 2017 *)

Crossrefs

Cf. A006882, A071828, A290046.

Sequence in context: A106025 A157959 A364134 * A094213 A321382 A153924

Adjacent sequences: A290044 A290045 A290046 * A290048 A290049 A290050

Keyword

easy,nonn,fini,full

Author

XU Pingya, Jul 19 2017

Status

approved