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A282941
a(n) = A000730(7*n).
4
1, 41, -176, 98, 322, -181, -140, -489, 112, 889, 14, -560, 125, 154, 756, -1317, -1778, 1554, -1218, 2688, 1764, -980, 71, -1575, 14, -1638, -419, 56, -1988, -2716, 6223, 6860, 1302, -700, -3416, -4733, -2548, -4725, 3836, 1106, 2631, 5096, -5656, 2660, -7875
OFFSET
0,2
REFERENCES
G. E. Andrews and B. C. Berndt, Ramanujan's lost notebook, Part III, Springer, New York, 2012, See p. 191.
LINKS
FORMULA
G.f.: Product_{n>=1} (1 - q^n)^8/(1 - q^(7*n)) + 49*q*(Product_{n>=1} (1 - q^n)^4*(1 - q^(7*n))^3).
a(n) = (-1)^j mod 7 if n = j*(3*j - 1)/2 for all j in Z; otherwise a(n) = 0 mod 7.
a(n) = A282942(n) mod 49.
EXAMPLE
G.f.: 1 + 41*q - 176*q^2 + 98*q^3 + 322*q^4 - 181*q^5 - 140*q^6 - 489*q^7 + ...
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Feb 25 2017
STATUS
approved