A130434 - OEIS

%I #22 Mar 31 2024 02:07:52

%S 6,16806,29234,67798,791578,1234806,1807566,2427706,12562534,29147626,

%T 29783134,38357866,41716918,50167486,99392626,111664666,162474586,

%U 169707826,281780346,286351066,349880326,423200566,463054594,479581642

%N Even pseudoprimes to base 7.

%H Amiram Eldar, <a href="/A130434/b130434.txt">Table of n, a(n) for n = 1..163</a> (terms below 10^12, calculated from the b-file at A005938; terms 1..37 from Robert G. Wilson v)

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/FermatPseudoprime.html">Fermat Pseudoprime</a>.

%H <a href="/index/Ps#pseudoprimes">Index entries for sequences related to pseudoprimes</a>.

%t lst = {}; Do[ If[ PowerMod[7, 2n - 1, 2n] == 1, AppendTo[lst, 2n]; Print[2n]], {n, 2, 24000000}]; lst (* _Robert G. Wilson v_, May 28 2007 *)

%Y Cf. A005938, A006935, A130433, A090082, A090083, A090084, A090085, A130435, A130436, A130437, A130438, A130439, A130440, A130441, A130442, A130443.

%K nonn

%O 1,1

%A _Alexander Adamchuk_, May 26 2007

%E a(9)-a(37) from _Robert G. Wilson v_, May 28 2007