A128158 a(n) = least k such that the remainder when 18^k is divided by k is n.

17, 14, 5, 7, 13, 106, 11, 158, 927, 314, 6767, 15, 724317787, 62, 21, 20, 407, 19, 319, 38, 39, 302, 150698261, 30, 1055599, 298, 129, 74

Offset

1,1

Comments

10^15 < a(29) <= 3612834616189533302730621726282897865691021. - Max Alekseyev, Apr 14 2012

Links

Table of n, a(n) for n=1..28.

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

Mathematica

t = Table[0, {10000}]; k = 1; While[k < 3000000000, a = PowerMod[18, k, k]; If[a < 10001 && t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k++ ]; t (* Robert G. Wilson v, Jun 23 2009 *)

Crossrefs

Cf. A036236, A078457, A119678, A119679, A127816, A119715, A119714, A127817, A127818, A127819, A127820, A127821, A128154, A128155, A128156, A128157, A128159, A128160, A128149, A128150.

Sequence in context: A357190 A195534 A373469 * A278824 A085095 A004506

Adjacent sequences: A128155 A128156 A128157 * A128159 A128160 A128161

Keyword

hard,more,nonn

Author

Alexander Adamchuk, Feb 16 2007

Extensions

a(13)-a(28) from Robert G. Wilson v, Jun 23 2009

Status

approved