A121990 - cp's OEIS frontend

A121990 Expansion of x(1+9x+2x^2)/((1-x)(1-3*x+x^2)).

n	a(n)
1	1
2	13
3	50
4	149
5	409
6	1090
7	2873
8	7541
9	19762
10	51757
11	135521
12	354818
13	928945
14	2432029
15	6367154
16	16669445
17	43641193
18	114254146
19	299121257
20	783109637
21	2050207666
22	5367513373
23	14052332465
24	36789484034
25	96316119649
26	252158874925

[1, 13, 50, 149, 409, 1090, 2873, 7541, 19762, 51757, 135521, 354818, 928945, 2432029, 6367154, 16669445, 43641193, 114254146, 299121257, 783109637, 2050207666, 5367513373, 14052332465, 36789484034, 96316119649, 252158874925]

cp's OEIS Frontend

A121990 Expansion of x(1+9x+2x^2)/((1-x)(1-3*x+x^2)).

Table of values

List of values

cp's OEIS Frontend

A121990 Expansion of x*(1+9*x+2*x^2)/((1-x)*(1-3*x+x^2)).

Table of values

List of values

A121990 Expansion of x(1+9x+2x^2)/((1-x)(1-3*x+x^2)).