login

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”).

A001117 as a simple table

na(n)
01
10
20
36
436
5150
6540
71806
85796
918150
1055980
11171006
12519156
131569750
144733820
1514250606
1642850116
17128746950
18386634060
191160688606
203483638676
2110454061750
2231368476700
2394118013006
24282379204836
25847187946150
262541664501740
277625194831806

[1,0,0,6,36,150,540,1806,5796,18150,55980,171006,
 519156,1569750,4733820,14250606,42850116,
 128746950,386634060,1160688606,3483638676,
 10454061750,31368476700,94118013006,282379204836,
 847187946150,2541664501740,7625194831806]