A220982 a(n) = 6^(4n+2) + 6^(3n+2) + 3 * 6^(2n+1) + 6^(n+1) + 1: the right Aurifeuillian factor of 6^(12n+6) + 1.

97, 55117, 62169337, 78727802257, 101638351073377, 131638631590149697, 170585384377200633217, 221074709452366968135937, 286511970539849391404729857, 371319329591314394530363646977, 481229811357035602199451623479297

Offset

0,1

Comments

The corresponding left Aurifeuillian factor is A220981.

Links

Table of n, a(n) for n=0..10.

Wikipedia, Cunningham Project

Index entries for linear recurrences with constant coefficients, signature (1555,-345210,12427560,-72550080,60466176).

Formula

Aurifeuillian factorization: 6^(12n+6) + 1 = (6^(4n+2) + 1) * A220981(n) * a(n).

G.f.: -(162922752*x^4-124050528*x^3+9947772*x^2-95718*x+97) / ((x-1)*(6*x-1)*(36*x-1)*(216*x-1)*(1296*x-1)). [Colin Barker, Jan 03 2013]

Mathematica

Table[6^(4n+2) + 6^(3n+2) + 3 * 6^(2n+1) + 6^(n+1) + 1, {n, 0, 20}]

Crossrefs

Cf. A092440, A085601, A220978, A198410, A220979-A220990.

Sequence in context: A173354 A176135 A160489 * A193825 A338779 A209475

Adjacent sequences: A220979 A220980 A220981 * A220983 A220984 A220985

Keyword

nonn,easy

Author

Stuart Clary, Dec 27 2012

Status

approved