%I #7 Aug 01 2015 04:51:34
%S 5,3,23,6,7,10,19,9,17,18,15,92,18881,319,36091,20,203,94,49,21,42395,
%T 42,17553,326,106709,27,2062919,36,14099,34,35,46,850984699,214,5847,
%U 44,341,58,377,106,105,634,301265879,158,93107,90,759,176,187,69,685,78
%N a(n) = least k such that the remainder when 26^k is divided by k is n.
%H Robert G. Wilson v, <a href="/A128366/a128366.txt">Table of n, a(n) for n = 1..10000 with -1 for large entries where a(n) has not yet been found</a>
%t t = Table[0, {10000}]; k = 1; lst = {}; While[k < 1200000000, a = PowerMod[26, k, k]; If[a < 10001 && t[[a]] == 0, t[[a]] = k; Print[{a, k}]; If[a + 1 == k, AppendTo[lst, a]; Print@lst]]; k++ ]; lst (* _Robert G. Wilson v_, Jun 30 2009 *)
%Y Cf. A128361, A128362, A128363, A128364, A128365, A128367, A128368, A128369, A129370, A128371, A128372.
%Y Cf. A036236, A078457, A119678, A119679, A127816, A119715, A119714, A127817, A127818, A127819, A127820, A127821, A128154, A128155, A128156, A128157, A128158, A128159, A128160.
%Y Cf. A128149, A128150, A128172.
%K hard,nonn
%O 1,1
%A _Alexander Adamchuk_, Feb 27 2007
%E a(27) - a(52) from _Robert G. Wilson v_, Jun 30 2009