OFFSET
1,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..50
A. Gainer-Dewar, Pólya theory for species with an equivariant group action, arXiv:1401.6202 [math.CO], 2014. Also Andrew Gainer-Dewar, Species with an equivariant group action, AUSTRALASIAN JOURNAL OF COMBINATORICS, Volume 63(2) (2015), Pages 202-225.
V. A. Liskovets, Some easily derivable sequences, J. Integer Sequences, 3 (2000), #00.2.2.
MATHEMATICA
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, May 24 2000
STATUS
approved