A014547 - OEIS (original) (raw)

A014547

n-th Euler (secant, zig) number [A000364](/A000364 "Euler (or secant or "Zig") numbers: e.g.f. (even powers only) sec(x) = 1/cos(x).")(n) is prime.

2

2, 3, 19, 227, 255

(list;graph;refs;listen;history;text;internal format)

OFFSET

1,1

LINKS

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

Eric Weisstein's World of Mathematics, Euler Number.

Eric Weisstein's World of Mathematics, Integer Sequence Primes

MATHEMATICA

Select[Range[100], PrimeQ[EulerE[#]] &]/2 (* Harvey P. Dale, Aug 10 2011 *)

CROSSREFS

Cf. [A000364](/A000364 "Euler (or secant or "Zig") numbers: e.g.f. (even powers only) sec(x) = 1/cos(x).").

Sequence in context: A061490 A048827 [A032077](/A032077 ""BHJ" (reversible, identity, labeled) transform of 2,1,1,1...") * A066735 A232498 A254380

Adjacent sequences: A014544 A014545 A014546 * A014548 A014549 A014550

KEYWORD

more,nonn

AUTHOR

Eric W. Weisstein

EXTENSIONS

Offset corrected by Arkadiusz Wesolowski, Oct 17 2011

STATUS

approved