A094171 Number of quasi-tetrominoes in an n X n bounding box.

0, 0, 1, 20, 147, 670, 2239, 6138, 14531, 30904, 60369, 110300, 190671, 314910, 500247, 768810, 110300, 190671, 314910, 500247, 768810, 1147959, 1671648

Offset

0,4

Links

Table of n, a(n) for n=0..22.

Erich Friedman, Illustration of initial terms

Example

See A094170 for example of similar sequence.

Crossrefs

Cf. A094170, A094172.

Sequence in context: A190067 A238021 A183959 * A100190 A189494 A022680

Adjacent sequences: A094168 A094169 A094170 * A094172 A094173 A094174

Keyword

nonn

Author

Jon Wild, May 07 2004

Extensions

Corrected and extended by Jon Wild, May 11 2004

Status

approved