A006147 Reversion of Ramanujan numbers.

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

Offset

1,2

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.

Formula

REVERT(A000594).

Example

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

Mathematica

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

Crossrefs

Cf. A000594.

Sequence in context: A227666 A107391 A281778 * A061236 A266997 A359644

Adjacent sequences: A006144 A006145 A006146 * A006148 A006149 A006150

Keyword

nonn

Author

N. J. A. Sloane

Extensions

Signs corrected Dec 24 2001

Status

approved