A030809 a(n) = floor(exp(20/23) * n!).

2, 4, 14, 57, 286, 1717, 12024, 96198, 865785, 8657857, 95236427, 1142837124, 14856882614, 207996356596, 3119945348943, 49919125583092, 848625134912575, 15275252428426350, 290229796140100651, 5804595922802013034

Offset

1,1

Links

Table of n, a(n) for n=1..20.

Example

20/23 = 0.869565217391304347826...
e^(20/23) = 2.38587329176990525818375327... so a(1) = 2.
e^(20/23) * 2! = 4.77174658353981051636750654... so a(2) = 4.
e^(20/23) * 3! = 14.3152397506194315491... so a(3) = 14.

Mathematica

Floor[Exp[20/23] Range[20]!] (* Harvey P. Dale, Sep 14 2019 *)

Crossrefs

Sequence in context: A030830 A059687 A030909 * A030958 A030885 A006384

Adjacent sequences: A030806 A030807 A030808 * A030810 A030811 A030812

Keyword

nonn,easy

Author

Simon Plouffe

Status

approved