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”).

A205680 as a simple table

na(n)
13
23
37
45
55
613
73
87
911
103
117
1211
1319
145
1513
1617
173
187
1911
2019
2123
225
2313
2417
2529
265
2713
2817
2929
3037
313
327
3311
3419
3523
3631
373
387
3911
4019
4123
4231
4343
445
4513
4617
4729
4837
4941
503
517
5211
5319
5423
5531
5643
5747
585
5913
6017
6129
6237
6341
6453
653
667
6711
6819
6923
7031
7143
7247
7359
743
757

[3,3,7,5,5,13,3,7,11,3,7,11,19,5,13,17,3,7,11,19,
 23,5,13,17,29,5,13,17,29,37,3,7,11,19,23,31,3,7,
 11,19,23,31,43,5,13,17,29,37,41,3,7,11,19,23,31,
 43,47,5,13,17,29,37,41,53,3,7,11,19,23,31,43,47,
 59,3,7]