OFFSET
0,2
LINKS
Ray Chandler, Table of n, a(n) for n = 0..834 (terms < 10^1000)
Steven R. Finch, Signum equations and extremal coefficients, February 7, 2009. [Cached copy, with permission of the author]
FORMULA
EXAMPLE
a(1)=2: give either the set {1,4} to A and {2,3} to B or give {2,3} to A and {1,4} to B.
MATHEMATICA
a[n_] := Coefficient[Product[q^(-k) + q^k, {k, 1, 4*n}], q, 0]; Table[a[n], {n, 0, 17}] (* Jean-François Alcover, Sep 26 2013 *)
CROSSREFS
KEYWORD
nice,nonn
AUTHOR
Roland Bacher, Mar 15 2001
STATUS
approved