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”).

A027617 as a simple table

na(n)
00
10
20
32
48
540
6200
71400
811200
9103040
101030400
1111334400
12135766400
131764963200
1424709484800
15370687116800
165930993868800
17100826895769600
181814871926067200
1934482566595276800
20689651331905536000
2114482682605174784000
22318619017313845248000

[0,0,0,2,8,40,200,1400,11200,103040,1030400,
 11334400,135766400,1764963200,24709484800,
 370687116800,5930993868800,100826895769600,
 1814871926067200,34482566595276800,
 689651331905536000,14482682605174784000,
 318619017313845248000]