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.

A333458 Irregular table read by rows: Take a diagonal-edged (or diamond-shaped) checkerboard with all diagonals drawn, as in A333434. Then T(n,k) = number of k-sided polygons in that figure for k >= 3.

Original entry on oeis.org

4, 84, 20, 692, 312, 72, 4, 2708, 2020, 400, 88, 0, 4, 7876, 5764, 1580, 264, 20, 4, 18220, 14868, 4960, 904, 112, 24, 36764, 30624, 11224, 2496, 304, 52, 66004, 55192, 18624, 3952, 472, 48, 111764, 97840, 40008, 9912, 1740, 244, 36, 175156, 158280, 63632, 15744, 2560, 156, 8, 16
Offset: 1

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Comments

See A333434 for the definition and images of the checkerboard.

Examples

			Table begins:
4;
84, 20;
692, 312, 72, 4;
2708, 2020, 400, 88, 0, 4;
7876, 5764, 1580, 264, 20, 4;
18220, 14868, 4960, 904, 112, 24;
36764, 30624, 11224, 2496, 304, 52;
66004, 55192, 18624, 3952, 472, 48;
111764, 97840, 40008, 9912, 1740, 244, 36;
175156, 158280, 63632, 15744, 2560, 156, 8, 16;
...
		

Crossrefs

Cf. A333434 (regions), A333459 (vertices), A333460 (edges), A331911, A331451, A333025, A333037.

Extensions

a(32) and beyond from Lars Blomberg, Jun 03 2020