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”).

A207831 as a triangular array

1
23
469
711514
815262135
101833593873
132341741339522
12254889163306543
162853101190275712279
203664117218408381324202123
19397513925647466315639437314
3251901653045608615246717226549

A207831 as a square array

1247810131216201932
36111518232528363951
952633414853647590
1421597489101117139165
3538133163190218256304
73953027408474560
2265573816686
43122324315152
79202639467
123437172
314265
49
1247810131216201932
36111518232528363951
952633414853647590
1421597489101117139165
3538133163190218256304
73953027408474560
2265573816686
43122324315152
79202639467
123437172
314265
49