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A247033
Numbers of the form (3^k - 3)/k.
1
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.
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
KEYWORD
nonn
AUTHOR
STATUS
approved