A173219 - cp's OEIS frontend

A173219 G.f.: A(x) = Sum_{n>=0} (1 + x)^(n(n+1)/2) / 2^(n+1).

n	a(n)
0	1
1	2
2	12
3	124
4	1800
5	33648
6	769336
7	20796960
8	648841680
9	22945907520
10	907036108432
11	39631833652320
12	1896696894062880
13	98669609894805600
14	5543804125505195040
15	334563594743197602272
16	21583554094995765302592

[1, 2, 12, 124, 1800, 33648, 769336, 20796960, 648841680, 22945907520, 907036108432, 39631833652320, 1896696894062880, 98669609894805600, 5543804125505195040, 334563594743197602272, 21583554094995765302592]

cp's OEIS Frontend

A173219 G.f.: A(x) = Sum_{n>=0} (1 + x)^(n(n+1)/2) / 2^(n+1).

Table of values

List of values