OFFSET
1,4
COMMENTS
Subset of foldings of n labeled stamps (A000136). - Stéphane Legendre, Apr 09 2013
LINKS
Stéphane Legendre, Table of n, a(n) for n = 1..42
S. Legendre, Foldings and Meanders, arXiv preprint arXiv:1302.2025 [math.CO], 2013.
S. Legendre, Foldings and Meanders, Aust. J. Comb. 58(2), 275-291, 2014.
FORMULA
A217318(n) = a(n) if n is odd and A217318(n) = (1/2)*a(n) if n is even. - Stéphane Legendre, Jan 13 2014
MATHEMATICA
a[n_] := (2 - Mod[n, 2]) A217318[[n]];
Array[a, 42] (* Jean-François Alcover, Sep 02 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Mar 29 2013
EXTENSIONS
Name clarified by Stéphane Legendre, Apr 09 2013
More terms from Stéphane Legendre, Apr 09 2013
STATUS
approved