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”).

A003727 as a simple table

na(n)
01
11
21
34
413
536
6181
7848
83865
923824
10140521
11871872
126324517
1344942912
14344747677
152860930816
1623853473329
17213856723200
181996865965009
1919099352929280
20193406280000061
212010469524579328
2221615227339380357
23242177953175506944

[1,1,1,4,13,36,181,848,3865,23824,140521,871872,
 6324517,44942912,344747677,2860930816,23853473329,
 213856723200,1996865965009,19099352929280,
 193406280000061,2010469524579328,
 21615227339380357,242177953175506944]