A128154 a(n) = least k such that the remainder when 14^k is divided by k is n.

13, 3, 11, 5, 33, 10, 1967, 9, 23587, 18, 2733, 46, 17651, 15, 93929, 20, 303, 178, 145, 22, 12901, 58, 2721, 25, 17990951, 27, 143, 36, 85, 166, 646123, 82, 2439143677, 55, 63, 76, 319, 123, 295, 52, 51, 77, 247380287953, 45, 5779134947, 90, 87, 74, 175, 146

Offset: 1

Author

Alexander Adamchuk, Feb 16 2007

Keywords

• hard
• nonn

Links

• Robert G. Wilson v, Table of n, a(n) for n = 1..10000 with -1 for large entries where a(n) has not yet been found

Crossrefs

Cf. A036236, A078457, A119678, A119679, A127816, A119715, A119714, A127817, A127818, A127819, A127820, A127821, A128155, A128156, A128157, A128158, A128159, A128160, A128149, A128150.

Programs

Mathematica

t = Table[0, {10000} ]; k = 1; While[ k < 3000000000, a = PowerMod[14, k, k]; If[a < 10001 && t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k++ ]; t
lk[n_]:=Module[{k=1},While[PowerMod[14,k,k]!=n,k++];k]; Array[lk,20] (* Harvey P. Dale, Aug 17 2013 *)

Extensions

More terms from Ryan Propper, Feb 28 2007

a(43) from Hagen von Eitzen, Aug 16 2009