A128684 Numbers k such that k^3 divides 11^(k^2) + 1.

1, 3, 111, 24753, 1770231, 23401797, 39402669, 65498547, 298100379, 440377293, 1788478509, 5218600731, 8786795187, 14606175981, 24342867543, 45340639419, 98204136339, 5032808252679, 5293823142513, 6241891310439, 7013907181779

Offset

1,2

Comments

3 divides a(n) for n > 1.

Links

Table of n, a(n) for n=1..21.

Mathematica

Select[Range[5*10^6], Mod[ 11^(#^2)+1, #^3]==0 &] (* G. C. Greubel, Jan 18 2018 *)

Crossrefs

Cf. A127263, A128677, A128678, A128679, A128680, A128681, A128682, A128683, A128685.

Sequence in context: A232769 A066138 A114207 * A292336 A037116 A169996

Adjacent sequences: A128681 A128682 A128683 * A128685 A128686 A128687

Keyword

nonn

Author

Alexander Adamchuk, Mar 31 2007

Extensions

a(5) from J. Mulder (jasper.mulder(AT)planet.nl), Jan 26 2010

Terms from a(6) onward from Max Alekseyev, May 14 2010

Status

approved