OFFSET
0,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..1000
Chai Wah Wu, Recurrence formula and generating function
MATHEMATICA
a[n_] := SeriesCoefficient[1/(1-x) Sum[x^(i^2), {i, -10, 10}]^n, {x, 0, 100}];
a /@ Range[0, 18] (* Jean-François Alcover, Sep 29 2019, from A302997 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved