A121681 - cp's OEIS frontend

A121681 a(n) = A121680(n)/(n+1) = [x^n] (1 + x*(1+x)^(n+1) )^(n+1) / (n+1).

n	a(n)
0	1
1	1
2	4
3	19
4	131
5	1136
6	11670
7	138727
8	1864711
9	27843874
10	456081803
11	8114074563
12	155519173031
13	3189879446235
14	69629136671356
15	1609836360587087
16	39262941548917619
17	1006616998791629666
18	27044968746461571213

[1, 1, 4, 19, 131, 1136, 11670, 138727, 1864711, 27843874, 456081803, 8114074563, 155519173031, 3189879446235, 69629136671356, 1609836360587087, 39262941548917619, 1006616998791629666, 27044968746461571213]

cp's OEIS Frontend

A121681 a(n) = A121680(n)/(n+1) = [x^n] (1 + x*(1+x)^(n+1) )^(n+1) / (n+1).

Table of values

List of values