A014531 - cp's OEIS frontend

A014531 Form array in which n-th row is obtained by expanding (1+x+x^2)^n and taking the 2nd column from the center.

n	a(n)
1	1
2	3
3	10
4	30
5	90
6	266
7	784
8	2304
9	6765
10	19855
11	58278
12	171106
13	502593
14	1477035
15	4343160
16	12778152
17	37616427
18	110797569
19	326527350
20	962803170
21	2840372304
22	8383467708
23	24755608584
24	73133433800
25	216143407675
26	639062383401

[1, 3, 10, 30, 90, 266, 784, 2304, 6765, 19855, 58278, 171106, 502593, 1477035, 4343160, 12778152, 37616427, 110797569, 326527350, 962803170, 2840372304, 8383467708, 24755608584, 73133433800, 216143407675, 639062383401]

cp's OEIS Frontend

A014531 Form array in which n-th row is obtained by expanding (1+x+x^2)^n and taking the 2nd column from the center.

Table of values

List of values