A002600 A generalized partition function.

1, 10, 25, 37, 42, 48, 79, 145, 244, 415, 672, 1100, 1722, 2727, 4193, 6428, 9658, 14478, 21313, 31304, 45329, 65311, 93074, 132026, 185413, 259242, 359395, 495839, 679175, 926064, 1254360, 1691753, 2268267, 3028345, 4021954, 5320139, 7003154

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

References

• Hansraj Gupta, A generalization of the partition function. Proc. Nat. Inst. Sci. India 17 (1951), 231-238.
• N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000
• Hansraj Gupta, A generalization of the partition function, Proc. Nat. Inst. Sci. India 17 (1951), 231-238. [Annotated scanned copy]

Programs

Maple

J:= m-> product((1-x^j)^(-j), j=1..m): a:= t-> coeff(series(J(min(6, t)), x, 1+max(6, t)), x, max(6, t)): seq(a(n), n=1..40); # Alois P. Heinz, Jul 20 2009

Mathematica

J[m_] := Product[(1-x^j)^-j, {j, 1, m}]; a[t_] := SeriesCoefficient[J[Min[6, t]], {x, 0, Max[6, t]}]; Table[a[n], {n, 1, 40}] (* Jean-François Alcover, Mar 13 2014, after Alois P. Heinz *)

Extensions

More terms from Alois P. Heinz, Jul 20 2009