A262394 - cp's OEIS frontend

A262394 a(n) = (1/n)Sum_{k=1..n} kbinomial(n,k-1)binomial(2n,n-k).

n	a(n)
1	1
2	4
3	20
4	110
5	637
6	3808
7	23256
8	144210
9	904475
10	5722860
11	36463440
12	233646504
13	1504152860
14	9721421440
15	63040282096
16	409972529754
17	2672860120455
18	17464206951100
19	114330456032100
20	749760805916430

[1, 4, 20, 110, 637, 3808, 23256, 144210, 904475, 5722860, 36463440, 233646504, 1504152860, 9721421440, 63040282096, 409972529754, 2672860120455, 17464206951100, 114330456032100, 749760805916430]

cp's OEIS Frontend

A262394 a(n) = (1/n)Sum_{k=1..n} kbinomial(n,k-1)binomial(2n,n-k).

Table of values

List of values

cp's OEIS Frontend

A262394 a(n) = (1/n)*Sum_{k=1..n} k*binomial(n,k-1)*binomial(2*n,n-k).

Table of values

List of values

A262394 a(n) = (1/n)Sum_{k=1..n} kbinomial(n,k-1)binomial(2n,n-k).