A370170 - cp's OEIS frontend

A370170 Coefficient of x^n in the expansion of (1+x+x^2)^(3*n).

n	a(n)
0	1
1	3
2	21
3	156
4	1221
5	9828
6	80580
7	669294
8	5612805
9	47419905
10	402993396
11	3441242544
12	29502452868
13	253778827695
14	2189249293266
15	18932541179706
16	164081616775173
17	1424741956592535
18	12392093363519415
19	107946143556797700
20	941580123046540596

[1, 3, 21, 156, 1221, 9828, 80580, 669294, 5612805, 47419905, 402993396, 3441242544, 29502452868, 253778827695, 2189249293266, 18932541179706, 164081616775173, 1424741956592535, 12392093363519415, 107946143556797700, 941580123046540596]

cp's OEIS Frontend

A370170 Coefficient of x^n in the expansion of (1+x+x^2)^(3*n).

Table of values

List of values