A127905 - cp's OEIS frontend

A127905 Construct triangle in which n-th row is obtained by expanding (1+x+x^3)^n and take the next-to-central column.

n	a(n)
0	0
1	1
2	2
3	3
4	8
5	25
6	66
7	168
8	456
9	1269
10	3490
11	9581
12	26544
13	73944
14	206220
15	576045
16	1613264
17	4527661
18	12725946
19	35818135
20	100950440
21	284869263
22	804726934
23	2275500998
24	6440230392
25	18242735800
26	51714552656

[0, 1, 2, 3, 8, 25, 66, 168, 456, 1269, 3490, 9581, 26544, 73944, 206220, 576045, 1613264, 4527661, 12725946, 35818135, 100950440, 284869263, 804726934, 2275500998, 6440230392, 18242735800, 51714552656]

cp's OEIS Frontend

A127905 Construct triangle in which n-th row is obtained by expanding (1+x+x^3)^n and take the next-to-central column.

Table of values

List of values