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.

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

1,1

Comments

See A333434 for the definition and images of the checkerboard.

Links

Lars Blomberg, Table of n, a(n) for n = 1..201 (the first 27 rows)

Example

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.

Sequence in context: A248382 A292409 A345989 * A119514 A316490 A102982

Adjacent sequences: A333455 A333456 A333457 * A333459 A333460 A333461

Keyword

nonn,tabf

Author

Scott R. Shannon and N. J. A. Sloane, Mar 22 2020

Extensions

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

Status

approved