A089709 - cp's OEIS frontend

A089709 a(1) = 1, a(2) = 2; for n>2, a(n) = sum_{r=1..n} {sum of all previous terms taken r at a time}.

n	a(n)
1	1
2	2
3	6
4	36
5	360
6	6480
7	220320
8	14541120
9	1890345600
10	487709164800
11	250682510707200
12	257200255985587200
13	527260524770453760000
14	2160713630509319508480000
15	17704887488393364052485120000

[1, 2, 6, 36, 360, 6480, 220320, 14541120, 1890345600, 487709164800, 250682510707200, 257200255985587200, 527260524770453760000, 2160713630509319508480000, 17704887488393364052485120000]

cp's OEIS Frontend

A089709 a(1) = 1, a(2) = 2; for n>2, a(n) = sum_{r=1..n} {sum of all previous terms taken r at a time}.

Table of values

List of values