A360861 - cp's OEIS frontend

A360861 a(n) = Sum_{k=0..n} binomial(n, ceiling(k/2)) * binomial(n, floor(k/2)).

n	a(n)
0	1
1	2
2	7
3	22
4	81
5	281
6	1058
7	3830
8	14605
9	54127
10	208110
11	782761
12	3027038
13	11501478
14	44668692
15	170974710
16	666220005
17	2564271875
18	10018268150
19	38728479647
20	151631858378
21	588229029258
22	2307174835212
23	8975958379817
24	35258881445606
25	137501193282026
26	540821096592028

[1, 2, 7, 22, 81, 281, 1058, 3830, 14605, 54127, 208110, 782761, 3027038, 11501478, 44668692, 170974710, 666220005, 2564271875, 10018268150, 38728479647, 151631858378, 588229029258, 2307174835212, 8975958379817, 35258881445606, 137501193282026, 540821096592028]

cp's OEIS Frontend

A360861 a(n) = Sum_{k=0..n} binomial(n, ceiling(k/2)) * binomial(n, floor(k/2)).

Table of values

List of values