A247033 Numbers of the form (3^k - 3)/k.

0, 3, 8, 48, 121, 312, 16104, 122640, 7596480, 61171656, 4093181688, 2366564736720, 19924948267224, 12169835294351280, 889585277491970400, 7633882962663652968, 565719454445904325272, 365721616371321130128240, 239498069351503974657030696, 2084811062715550992506283600

Offset

1,2

Comments

Generated by k: 1, 2, 3, 5, 6, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 66, 67, ...

Subsequence of A246445.

Links

Table of n, a(n) for n=1..20.

Example

121 is in this sequence because (3^k - 3)/k = (3^6 - 3)/6 = 121.

Crossrefs

Cf. A000040, A005935, A064535 (with form (2^k - 2)/k), A122780 (nonprimes k in a(n)), A246445, A247307 (with form (4^k - 4)/k).

Sequence in context: A019016 A063859 A210373 * A309578 A291504 A034183

Adjacent sequences: A247030 A247031 A247032 * A247034 A247035 A247036

Keyword

nonn

Author

Juri-Stepan Gerasimov, Sep 09 2014

Status

approved