A128365 a(n) = least k such that the remainder when 25^k is divided by k is n.

2, 23, 11, 7, 10, 19, 57, 17, 14, 15, 614, 13, 34

Offset: 1

Author

Alexander Adamchuk, Feb 27 2007

Keywords

• hard
• more
• nonn

Comments

a(14) > 10^15. - Max Alekseyev, Apr 14 2012

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
• Fausto A. C. Cariboni, Table of n, a(n) for n = 1..10000 with -1 for large entries where a(n) has not yet been found, Oct 30 2016 [With 182 new terms, this supersedes the earlier table from Robert G. Wilson v]

Crossrefs

Cf. A128361, A128362, A128363, A128364, A128366, A128367, A128368, A128369, A129370, A128371, A128372.

Cf. A036236, A078457, A119678, A119679, A127816, A119715, A119714, A127817, A127818, A127819, A127820, A127821, A128154, A128155, A128156, A128157, A128158, A128159, A128160.

Cf. A128149, A128150, A128172.

Programs

Mathematica

t = Table[0, {10000} ]; k = 1; While[ k < 4000000000, a = PowerMod[25, k, k]; If[a < 10001 && t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k++ ]; t (* Robert G. Wilson v, Aug 04 2009 *)