A181326 - cp's OEIS frontend

A181326 Number of columns with an odd sum in all 2-compositions of n. A 2-composition of n is a nonnegative matrix with two rows, such that each column has at least one nonzero entry and whose entries sum up to n.

n	a(n)
0	0
1	2
2	8
3	40
4	168
5	696
6	2776
7	10864
8	41800
9	158816
10	597176
11	2226512
12	8242344
13	30328160
14	111013784
15	404518640
16	1468154504
17	5309771264
18	19143323000
19	68823556368
20	246805713000
21	883028659744
22	3152718627672
23	11234773009200

[0, 2, 8, 40, 168, 696, 2776, 10864, 41800, 158816, 597176, 2226512, 8242344, 30328160, 111013784, 404518640, 1468154504, 5309771264, 19143323000, 68823556368, 246805713000, 883028659744, 3152718627672, 11234773009200]

cp's OEIS Frontend

A181326 Number of columns with an odd sum in all 2-compositions of n. A 2-composition of n is a nonnegative matrix with two rows, such that each column has at least one nonzero entry and whose entries sum up to n.

Table of values

List of values