A293459 Denominator of probability that a permutation of elements of some subset of set {1,2..n} is a permutation of elements of some set of the form 1..k, k <= n.

1, 1, 7, 385, 3628921, 1216452311762688721, 10333147966386144929717742279694909445041, 5989285834984945898036392571843137173092920925318860392502631168811983977451725959000900501504040321

Offset

1,3

Links

Amiram Eldar, Table of n, a(n) for n = 1..10

Mathematica

a[n_] := Denominator[Sum[k!, {k, 0, n}]/Sum[Binomial[n, k]!, {k, 0, n}]]; Array[a, 8] (* Amiram Eldar, Sep 21 2019 *)

Prog

(PARI) a(n) = denominator(sum(k=0, n, k!)/sum(k=0, n, binomial(n, k)!)); \\ Michel Marcus, Oct 12 2017

Crossrefs

Cf. A293458(numerators).

Sequence in context: A367868 A299036 A112905 * A058275 A184954 A185354

Adjacent sequences: A293456 A293457 A293458 * A293460 A293461 A293462

Keyword

nonn,frac

Author

Vladimir Shevelev, Oct 09 2017

Extensions

More terms from Peter J. C. Moses, Oct 09 2017

Status

approved