A172991 - OEIS

The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.

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A172991 as a triangular array

1

1 1

1 2 1

1 4 4 1

1 6 11 6 1

1 8 22 22 8 1

1 10 37 63 37 10 1

1 12 56 136 136 56 12 1

1 14 79 249 376 249 79 14 1

1 16 106 410 849 849 410 106 16 1

1 18 137 627 1663 2317 1663 627 137 18 1

1 20 172 908 2942 5371 5371 2942 908 172 20 1

1 22 211 1261 4826 11017 14545 11017 4826 1261 211 22 1

A172991 as a square array

1 1 1 1 1 1 1 1 1 1 1 1 1

1 2 4 6 8 10 12 14 16 18 20 22

1 4 11 22 37 56 79 106 137 172 211

1 6 22 63 136 249 410 627 908 1261

1 8 37 136 376 849 1663 2942 4826

1 10 56 249 849 2317 5371 11017

1 12 79 410 1663 5371 14545

1 14 106 627 2942 11017

1 16 137 908 4826

1 18 172 1261

1 20 211

1 22

1

A172991 as an upper right triangle