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”).

A189508 as a simple table

na(n)
11
23
321
4160
51620
619068
7264420
84166880
974011488
101459381440
1131674232128

[1,3,21,160,1620,19068,264420,4166880,74011488,
 1459381440,31674232128]