OFFSET
1,1
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..1000
T. R. S. Walsh and A. B. Lehman, Counting rooted maps by genus. III: Nonseparable maps, J. Combinatorial Theory Ser. B 18 (1975), 222-259.
Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).
FORMULA
From Colin Barker, Apr 09 2013: (Start)
a(n) = n*(n + 1)*(n + 2)*(8*n^3 + 87*n^2 + 148*n - 3)/360.
G.f.: x*(2*x^3+5*x^2-19*x-4) / (x-1)^7. (End)
MATHEMATICA
LinearRecurrence[{7, -21, 35, -35, 21, -7, 1}, {4, 47, 240, 831, 2282, 5362, 11256}, 40] (* Harvey P. Dale, May 15 2023 *)
PROG
(PARI) a(n) = {n*(n + 1)*(n + 2)*(8*n^3 + 87*n^2 + 148*n - 3)/360}
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Name clarified and terms a(11) and beyond from Andrew Howroyd, Apr 04 2021
STATUS
approved