A130436 Even pseudoprimes to base 17.

4, 8, 16, 1228, 4912, 5662, 11476, 76798, 168904, 387676, 938792, 1003276, 1147576, 1415044, 1419856, 1832836, 2297296, 3976624, 5470126, 6376126, 7309576, 9649624, 12423676, 13193776, 14026888, 14652496, 19136272, 20570936, 24604696

Offset: 1

Author

Alexander Adamchuk, May 26 2007

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..400 (terms 1..119 from Robert G. Wilson v)
• Eric Weisstein's World of Mathematics, Fermat Pseudoprime.
• Index entries for sequences related to pseudoprimes.

Crossrefs

Cf. A020145, A006935, A130433, A090082, A090083, A090084, A090085, A130434, A130435, A130437, A130438, A130439, A130440, A130441, A130442, A130443.

Programs

Mathematica

lst = {}; Do[ If[ PowerMod[17, 2n - 1, 2n] == 1, AppendTo[lst, 2n]], {n, 2, 2*10^9}]; lst (* Robert G. Wilson v, Jun 01 2007 *)

PARI

is(k) = k > 2 && !(k % 2) &&  Mod(17, k)^(k-1) == 1; \\ Amiram Eldar, Sep 18 2024

Extensions

a(13)-a(29) from Robert G. Wilson v, Jun 01 2007