OFFSET
1,1
COMMENTS
From Alexander Adamchuk, Jan 31 2007: (Start)
a(n) > n.
For numbers n such that a(n-1) = n, see A015951 except first term. (End)
a(58) <= 16860204577843069 from Joe K. Crump (joecr(AT)carolina.rr.com), Feb 06 2007
LINKS
Robert G. Wilson v, Table of n, a(n) for n = 1..10000 with -1 for those entries where a(n) has not yet been found [This file is now out of date - see the extension lines below. - N. J. A. Sloane, May 22 2010]
MATHEMATICA
Do[k = 1; While[PowerMod[5, k, k] != n, k++ ]; Print[k], {n, 30}]
Table[0, {10000}]; k = 1; lst = {}; While[k < 5000000000, a = PowerMod[5, k, k]; If[ a < 10001 && t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k++ ]; t (* changed (to reflect the new limits) by Robert G. Wilson v, Jul 14 2009 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Ryan Propper, Jun 12 2006
EXTENSIONS
Revised by Max Alekseyev, Sep 25 2007
a(172) = 26598818717 = 23 * 593 * 1039 * 1877, a(288) = 9158745413 = 241 * 347 * 109519, a(518) = 33288260241 = 3 * 43 * 258048529, a(558) = 7722115807 = 7 * 157 * 7026493 from Daniel Morel, May 18 2010
a(848) = 6672480963 = 3 * 241 * 9228881 from Daniel Morel, May 26 2010
a(416) = 10545901269 from Daniel Morel, Jul 05 2010
a(948) = 146246024857 from Daniel Morel, Jul 12 2010
a(822) = 466661006683 from Daniel Morel, Aug 24 2010
STATUS
approved