A138903 - cp's OEIS frontend

A138903 a(n) = (1/2^n)* Sum_{k=0..n} binomial(n,k)*(n+k)^(n-1).

n	a(n)
1	1
2	3
3	21
4	234
5	3590
6	70254
7	1672972
8	46955760
9	1517994792
10	55549351800
11	2269918543640
12	102452561694864
13	5062050729973120
14	271751784988056576
15	15750949414628405760
16	980315266648197537792
17	65207656047198387921536

[1, 3, 21, 234, 3590, 70254, 1672972, 46955760, 1517994792, 55549351800, 2269918543640, 102452561694864, 5062050729973120, 271751784988056576, 15750949414628405760, 980315266648197537792, 65207656047198387921536]

cp's OEIS Frontend

A138903 a(n) = (1/2^n)* Sum_{k=0..n} binomial(n,k)*(n+k)^(n-1).

Table of values

List of values