A073431 - 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

A073431 as a simple table

n	a(n)
0	1
1	1
2	1
3	2
4	3
5	6
6	12
7	28
8	65
9	160
10	408
11	1074
12	2898
13	7998
14	22508
15	64426
16	187251
17	551730
18	1645840
19	4964876
20	15130808
21	46545788
22	144424944
23	451715460

[1,1,1,2,3,6,12,28,65,160,408,1074,2898,7998, 22508,64426,187251,551730,1645840,4964876, 15130808,46545788,144424944,451715460]