OFFSET
0,2
REFERENCES
John Charles Saunders, Problems in Combinatorial and Analytic Number Theory, Ph. D. thesis, University of Waterloo, 2018.
LINKS
Paul Barry, Centered polygon numbers, heptagons and nonagons, and the Robbins numbers, arXiv:2104.01644 [math.CO], 2021.
Kevin G. Hare, and J. C. Saunders, On (a,b) Pairs in Random Fibonacci Sequences, Arxiv preprint, arXiv:1608.03522 [math.NT], February 2018.
FORMULA
From Vladimir Kruchinin, Sep 30 2023: (Start)
G.f.: (F(x) - 1)/(2 - F(x))^2/x, where F(x) is the g.f. of A001764.
a(n) = 3*Sum_{k=0..n} (k + 1)^2*C(3*n + 2, n - k)/(2*n + k + 3). (End)
CROSSREFS
KEYWORD
nonn
AUTHOR
Jeffrey Shallit, Jun 05 2018
STATUS
approved