A006147 Reversion of Ramanujan numbers.

1, 24, 900, 40352, 1994322, 104816880, 5747466920, 325077729600, 18826860841119, 1110900168420264, 66547088543789532, 4036419643768799328, 247405021070280491110, 15299980644645295780560, 953473460271200881693560, 59817824263728235912396224

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

Examples

			x + 24*x^2 + 900*x^3 + 40352*x^4 + 1994322*x^5 + 104816880*x^6 + ...
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..100
• G. Kreweras and Y. Poupard, Sur les partitions en paires d'un ensemble fini totalement ordonné, Publications de l'Institut de Statistique de l'Université de Paris, 23 (1978), 57-74. (Annotated scanned copy)
• Index entries for reversions of series.

Crossrefs

Cf. A000594.

Programs

Mathematica

Rest[CoefficientList[InverseSeries[Series[q * QPochhammer[q, q]^24, {q, 0, 16}]], q]] (* Amiram Eldar, Jan 06 2025 *)

Formula

REVERT(A000594).

Extensions

Signs corrected Dec 24 2001