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”).

A221994 as a simple table

na(n)
12
23
34
46
510
615
722
836
956
1084
11135
12211
13325
14510
15797
161234
171930
183015
194685
207316
2111420
2217781
2327736
2443274
2567431
26105156
27164021
28255685
29398698
30621785
31969445
321511643
332357276
343675552
355731237
368937024
3713935318
3821729235
3933882957

[2,3,4,6,10,15,22,36,56,84,135,211,325,510,797,
 1234,1930,3015,4685,7316,11420,17781,27736,43274,
 67431,105156,164021,255685,398698,621785,969445,
 1511643,2357276,3675552,5731237,8937024,13935318,
 21729235,33882957]