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A275633
Andrews's shadow difference function D_3(q).
3
0, 0, 0, 0, 0, 1, 1, 3, 4, 7, 10, 16, 20, 31, 41, 56, 74, 101, 129, 172, 219, 284, 363, 464, 581, 738, 924, 1155, 1435, 1785, 2199, 2717, 3332, 4084, 4987, 6076, 7375, 8949, 10817, 13051, 15706, 18877, 22622, 27078, 32332, 38545, 45870, 54496, 64618, 76525, 90463, 106788, 125863, 148145, 174106
OFFSET
0,8
COMMENTS
Agrees with A237833 just for n <= 21.
LINKS
FORMULA
Equals (A098151-A275632)/8.
MAPLE
F:=(a, q, n)->mul(1-a*q^i, i=0..n-1); # This is (a; q)_n
M:=15;
THETA3:=(add((-1)^n*q^(3*n^2), n=-M..M)) /(add((-1)^n*q^(n^2), n=-M..M));
s1:=series(THETA3, q, 80); seriestolist(%);
THETABAR3:=1+2*add( (F(q, q, n-1)*q^(n^2)) / (F(q^n, q, n)*(1-q^n)), n=1..M);
s2:=series(THETABAR3, q, 80); seriestolist(%);
series((s1-s2)/8, q, 80); seriestolist(%);
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Aug 09 2016
STATUS
approved