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”).

A309939 as a triangular array

1
11
121
1131
12341
113651
12361061
1137121571
123614222181
11381527372891
12361632505836101
1137163563888645111

A309939 as a square array

111111111111
12121212121
1333333333
146676867
15101214151616
161522273235
1721375063
18285888
193686
11045
111
1
111111111111
12121212121
1333333333
146676867
15101214151616
161522273235
1721375063
18285888
193686
11045
111
1