A121678 - cp's OEIS frontend

A121678 a(n) = [x^n] (1 + x*(1+x)^n )^(n+1).

n	a(n)
0	1
1	2
2	9
3	52
4	425
5	4236
6	49294
7	655096
8	9731313
9	159114880
10	2832245911
11	54400757016
12	1119436524947
13	24532373640334
14	569732648555295
15	13962373137304496
16	359767723241891425
17	9715902692094061488

[1, 2, 9, 52, 425, 4236, 49294, 655096, 9731313, 159114880, 2832245911, 54400757016, 1119436524947, 24532373640334, 569732648555295, 13962373137304496, 359767723241891425, 9715902692094061488]

cp's OEIS Frontend

A121678 a(n) = [x^n] (1 + x*(1+x)^n )^(n+1).

Table of values

List of values