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”).

A007847 as a simple table

na(n)
12
26
320
4140
53254
6252434
771343208
886246755608
9448691419804586

[2,6,20,140,3254,252434,71343208,86246755608,
 448691419804586]