A103234 Numbers k such that the k-th Euler number (A122045(k)) is prime.

4, 6, 38, 454, 510

Offset

1,1

Comments

Equals 2*A014547.

No others for k <= 69574 (Simon Plouffe). - Eric W. Weisstein, Aug 24 2020

No others for k <= 112130 (Simon Plouffe). - Eric W. Weisstein, Apr 15 2024

Links

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

Eric Weisstein's World of Mathematics, Euler Number

Eric Weisstein's World of Mathematics, Euler Number Prime

Eric Weisstein's World of Mathematics, Integer Sequence Primes

Mathematica

Position[EulerE[Range[600]], _?PrimeQ] // Flatten
Select[Range[600], PrimeQ @* EulerE] (* Eric W. Weisstein, Apr 12 2024 *)

Crossrefs

Cf. A000364, A014547, A122045 (EulerE), A092823.

Sequence in context: A092187 A092765 A056315 * A074061 A125081 A175349

Adjacent sequences: A103231 A103232 A103233 * A103235 A103236 A103237

Keyword

nonn,hard,more

Author

Eric W. Weisstein, Jan 26 2005

Status

approved