A127821 a(n) = least k such that the remainder of 13^k divided by k is n.

2, 11, 5, 51, 44, 7, 15, 371285, 10, 74853, 158, 13757837, 17, 5805311, 22, 2181, 38, 25, 30, 9667, 74, 87, 146, 23441, 88, 19629779, 35, 45, 70, 235433, 46, 55, 34, 309, 134

Offset: 1

Author

Alexander Adamchuk, Jan 30 2007

Keywords

• nonn
• hard
• more

Comments

a(36) > 10^16. - Max Alekseyev, Oct 25 2016

Links

• 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 31 2016 [With 207 new terms, this supersedes the earlier table from Robert G. Wilson v et al.]
• Doug Strain, Table of n, a(n) for n = 1..10000 with -1 for large entries where a(n) has not yet been found, [With more terms, this supersedes the earlier table from Fausto A. C. Cariboni and Robert G. Wilson v et al.]
• Robert G. Wilson v et al., Table of n, a(n) for n = 1..10000 with -1 for large entries where a(n) has not yet been found, Feb 06 2007; Nov 30 2010.

Crossrefs

Cf. A036236, A078457, A119678, A119679, A127816, A119715, A119714, A127817, A127818, A127819, A127820.

Programs

Mathematica

t = Table[0, {10000} ]; k = 1; While[ k < 3500000000, a = PowerMod[13, k, k]; If[a < 10001 && t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k++ ]; t

Extensions

More terms from Robert G. Wilson v, Feb 06 2007

a(264), a(798), a(884), a(896), a(976), a(980), a(152), a(171), a(296), a(464), a(824), a(870) from Daniel Morel, Jun 17, Nov 30 2010