A014532 - cp's OEIS frontend

A014532 Form array in which n-th row is obtained by expanding (1+x+x^2)^n and taking the 3rd column from the center.

n	a(n)
1	1
2	4
3	15
4	50
5	161
6	504
7	1554
8	4740
9	14355
10	43252
11	129844
12	388752
13	1161615
14	3465840
15	10329336
16	30759120
17	91538523
18	272290140
19	809676735
20	2407049106
21	7154586747
22	21263575256
23	63191778950
24	187790510700
25	558069593445
26	1658498131836

[1, 4, 15, 50, 161, 504, 1554, 4740, 14355, 43252, 129844, 388752, 1161615, 3465840, 10329336, 30759120, 91538523, 272290140, 809676735, 2407049106, 7154586747, 21263575256, 63191778950, 187790510700, 558069593445, 1658498131836]

cp's OEIS Frontend

A014532 Form array in which n-th row is obtained by expanding (1+x+x^2)^n and taking the 3rd column from the center.

Table of values

List of values