A030881 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A030881 as a simple table

n	a(n)
1	1
2	2
3	8
4	35
5	177
6	1062
7	7435
8	59485
9	535371
10	5353716
11	58890876
12	706690515
13	9186976699
14	128617673796
15	1929265106946
16	30868241711142
17	524760109089429
18	9445681963609723
19	179467957308584751
20	3589359146171695020

[1,2,8,35,177,1062,7435,59485,535371,5353716, 58890876,706690515,9186976699,128617673796, 1929265106946,30868241711142,524760109089429, 9445681963609723,179467957308584751, 3589359146171695020]