OFFSET
1,2
COMMENTS
Leroux asks: Is there a combinatorial interpretation for these numbers?
Those are the coefficients of the series reverse of the Poincaré series of the 5-Gonal operad, and not of the 5-Tetra operad. The sequence for the 5-Tetra operad is well-known and is A002294. - Paul Laubie, Nov 08 2023
LINKS
Ph. Leroux, A simple symmetry generating operads related to rooted planar m-ary trees and polygonal numbers, arXiv:math/0512437 [math.CO], 2005.
Ph. Leroux, A simple symmetry generating operads related to rooted planar m-ary trees and polygonal numbers, J. Integer Seqs., 10 (2007), #07.4.7.
FORMULA
G.f.: series reversion of -(2*t^2-t)/(1+t)^3. - Paul Laubie, Nov 08 2023
PROG
(Sage) R.<t>=PowerSeriesRing(QQ); (-(2*t^2-t)/(1+t)^3).reverse().list()[1:] # Paul Laubie, Nov 08 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 07 2006
EXTENSIONS
New offset, name corrected and more terms from Paul Laubie, Nov 08 2023
STATUS
approved