%I #11 Jan 18 2019 11:21:03
%S 23,11,7,5,19,10,17,142,15,566,13,78,5865637,205,13809,20,589,39,35,
%T 278,129,554,459207143,25,148731221,50,63,274,2855,33,49,34,5429,542,
%U 5528521301,42,2773,538,185,77,3220589,66,90553,956,2317,70,161,104
%N a(n) = least k such that the remainder when 24^k is divided by k is n.
%H Robert G. Wilson v, <a href="/A128364/a128364.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; While[k < 3600000000, a = PowerMod[25, k, k]; If[a < 10001 && t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k++ ]; t (* _Robert G. Wilson v_, Jun 29 2009 *)
%t lk[n_] := Module[{k = 1}, While[PowerMod[24, k, k] != n, k++]; k]; Array[ lk,48] (* _Harvey P. Dale_, Jan 18 2019 *)
%Y Cf. A128361, A128362, A128363, A128365, A128366, 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(13) - a(34) from _Robert G. Wilson v_, Jun 29 2009