A217616 - cp's OEIS frontend

A217616 G.f.: Sum_{n>=0} x^n * Sum_{k=0..n} binomial(n,k)^2 * x^k*(2-x)^(n-k).

n	a(n)
0	1
1	2
2	4
3	12
4	38
5	116
6	360
7	1144
8	3670
9	11836
10	38392
11	125160
12	409628
13	1345000
14	4428752
15	14618608
16	48356838
17	160260332
18	532009688
19	1768729736
20	5888250996
21	19626282328
22	65489004464
23	218743627408
24	731311554044
25	2447018357208
26	8194289368240
27	27459924376592

[1, 2, 4, 12, 38, 116, 360, 1144, 3670, 11836, 38392, 125160, 409628, 1345000, 4428752, 14618608, 48356838, 160260332, 532009688, 1768729736, 5888250996, 19626282328, 65489004464, 218743627408, 731311554044, 2447018357208, 8194289368240, 27459924376592]

cp's OEIS Frontend

A217616 G.f.: Sum_{n>=0} x^n * Sum_{k=0..n} binomial(n,k)^2 * x^k*(2-x)^(n-k).

Table of values

List of values