cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A213945 Triangle by rows, generated from aerated sequences of 1's.

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 1, 1, 1, 5, 1, 1, 1, 2, 11, 1, 1, 1, 1, 4, 24, 1, 1, 1, 1, 2, 7, 51, 1, 1, 1, 1, 1, 4, 12, 107, 1, 1, 1, 1, 1, 2, 6, 21, 222, 1, 1, 1, 1, 1, 1, 4, 9, 36, 457, 1, 1, 1, 1, 1, 1, 2, 6, 14, 61, 935, 1, 1, 1, 1, 1, 1, 1, 4, 8, 22, 103, 1904, 1, 1, 1, 1, 1, 1, 1, 2, 6, 11, 34, 173, 3863
Offset: 0

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Author

Gary W. Adamson, Jun 25 2012

Keywords

Comments

Row sums are powers of 2. The right border is a variant of A027934 in which the 0 of the latter is replaced by a 1.

Examples

			First few rows of the array are:
1, 2, 4, 8, 16, 32, 64, 128, 256,...
1, 1, 2, 3,..5,..8,.13,..21,..34,...
1, 1, 1, 2,..3,..4,..6,...9,..13,...
1, 1, 1, 1,  2,..3,..4,...5,...7,...
... Then, take finite differences from the top -> down, getting the triangle:
1;
1, 1;
1, 1, 2;
1, 1, 1, 5;
1, 1, 1, 2, 11;
1, 1, 1, 1, 4, 24;
1, 1, 1, 1, 2, 7, 51;
1, 1, 1, 1, 1, 4, 12, 107;
1, 1, 1, 1, 1, 2, 6, 21, 222;
1, 1, 1, 1, 1, 1, 4, 9, 36, 457;
...
		

Crossrefs

Cf. A027934.

Formula

Form an array in which rows are INVERT transforms of sequences of 1's starting (1,1,1,...) with row 0; then the INVERT transforms of 1's aerated with one zero (row 1); with two zeros, (row 2); three zeros, (row 3); and so on.