A143665 a(n) is the least prime such that the multiplicative order of 5 mod a(n) equals n.

2, 3, 31, 13, 11, 7, 19531, 313, 19, 521, 12207031, 601, 305175781, 29, 181, 17, 409, 5167, 191, 41, 379, 23, 8971, 390001, 101, 5227, 109, 234750601, 59, 61, 1861, 2593, 199, 3061, 211, 37, 149, 761, 79, 241, 2238236249, 43, 1644512641, 89, 1171, 47

Offset

1,1

Links

Max Alekseyev, Table of n, a(n) for n = 1..520

Mathematica

p = 2; t = Table[0, {100}]; While[p < 3000000001, a = MultiplicativeOrder[5, p]; If[0 < a < 101 && t[[a]] == 0, t[[a]] = p]; p = NextPrime@ p]; t (* Robert G. Wilson v, Oct 13 2014 *)

Crossrefs

Cf. A064081, A143663, A112092, A112927, A007138, A218357.

Sequence in context: A035514 A114009 A307453 * A074479 A272043 A136150

Adjacent sequences: A143662 A143663 A143664 * A143666 A143667 A143668

Keyword

nonn

Author

Vladimir Shevelev, Aug 28 2008

Extensions

a(23)-a(40) from Robert G. Wilson v, Oct 13 2014

a(41)-a(46) from Robert G. Wilson v, Oct 15 2014

Status

approved