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A059778
Expansion of 1 / product((1+q^(2*n+3))/(1-q^(2*n+2)), n=0..inf).
1
1, 0, -1, -1, -1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, -1, -1, 0, 0, 0, 0, -1, -1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, -1
OFFSET
0,1
COMMENTS
a(n) = (-1)^n*(t(n)-t(n-1)), n>0, where t(n) = A010054(n) is characteristic function of triangular numbers. - Vladeta Jovovic, Sep 22 2002
REFERENCES
G. E. Andrews, Three-quadrant Ferrers graphs, Indian J. Math., 42 (No. 1, 2000), 1-7.
CROSSREFS
Cf. A059777.
Sequence in context: A259599 A070749 A285341 * A355690 A359590 A104521
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Feb 21 2001
STATUS
approved