A101708 - OEIS

A101708

Number of partitions of n having positive even rank (the rank of a partition is the largest part minus the number of parts).

0, 0, 0, 1, 0, 2, 1, 4, 3, 7, 6, 14, 13, 23, 24, 41, 43, 67, 75, 111, 126, 177, 204, 282, 328, 437, 514, 674, 793, 1021, 1207, 1533, 1814, 2273, 2691, 3344, 3956, 4865, 5754, 7027, 8296, 10060, 11864, 14302, 16836, 20183, 23715, 28301, 33191, 39423, 46152, 54607, 63794, 75200, 87687, 103018

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OFFSET

0,6

REFERENCES

George E. Andrews, The Theory of Partitions, Addison-Wesley, Reading, Mass., 1976.

LINKS

Table of n, a(n) for n=0..55.

FORMULA

G.f.: Sum((-1)^(k+1)*x^((3*k^2+3*k)/2)/(1+x^k), k>=1)/Product(1-x^k, k>=1). - Vladeta Jovovic, Dec 20 2004

a(n) = A064173(n) - A101707(n) for n >= 1.

EXAMPLE

a(7)=4 because the only partitions of 7 with positive even rank are 7 (rank=6), 61 (rank=4), 511 (rank=2) and 43 (rank=2).