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”).

A197180 as a triangular array

1
11
252
310103
42341234
658150150586
91446659696651449
13363269571727172269536313
19917114245086492206508641142491719
282321475283678131096217109621736781347528232128

A197180 as a square array

1123469131928
151023581443639172321
2104115066526951142447528
323150969717250864367813
4586657172922061096217
61442695508641096217
936311424367813
1391747528
192321
28
1123469131928
151023581443639172321
2104115066526951142447528
323150969717250864367813
4586657172922061096217
61442695508641096217
936311424367813
1391747528
192321
28