A146268 - 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

A146268 as a simple table

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	1
7	2
8	5
9	10
10	17
11	30
12	77
13	254
14	873
15	2865
16	9282
17	36476
18	176379
19	950600
20	5334620
21	30998066
22	200015663
23	1516056134
24	12927161092
25	120013319909
26	1186872290095
27	12868902178120
28	156796551881590

[1,1,1,1,1,1,2,5,10,17,30,77,254,873,2865,9282, 36476,176379,950600,5334620,30998066,200015663, 1516056134,12927161092,120013319909,1186872290095, 12868902178120,156796551881590]