A130426 a(n) = denominator of Sum_{k=1..n} 1/k^(n+1-k).

1, 2, 12, 72, 1080, 129600, 54432000, 22861440000, 9601804800000, 4032758016000000, 18631342033920000000, 86076800196710400000000, 5169772619814426624000000000, 310496543546054463037440000000000

Offset

1,2

Links

Table of n, a(n) for n=1..14.

Mathematica

Table[Denominator[Sum[1/k^(n + 1 - k), {k, 1, n}]], {n, 1, 20}] (* Stefan Steinerberger, May 30 2007 *)

Crossrefs

Cf. A130425, A003101.

Sequence in context: A362796 A002867 A235359 * A002397 A163085 A328946

Adjacent sequences: A130423 A130424 A130425 * A130427 A130428 A130429

Keyword

frac,nonn

Author

Leroy Quet, May 26 2007

Extensions

More terms from Stefan Steinerberger, May 30 2007

Status

approved