A194995 Number of lower triangles of an n X n 0..5 array with each element differing from all of its horizontal and vertical neighbors by one

6, 18, 90, 672, 7858, 138956, 3816148, 159427052, 10305467946, 1016480307410, 154783529107972, 36032460970618398, 12930394865167766832, 7102572782942842968972, 6007897214058607933844528

Offset

1,1

Comments

Column 5 of A194998

Links

R. H. Hardin, Table of n, a(n) for n = 1..22

Example

Some solutions for 4X4
..1........4........2........1........1........3........2........4
..2.3......3.4......3.4......2.3......2.1......4.5......3.2......5.4
..3.2.1....4.3.4....2.3.2....3.2.3....1.2.3....5.4.3....2.3.4....4.3.2
..4.3.2.1..5.4.3.2..3.4.3.4..4.3.4.3..2.1.2.1..4.5.4.5..3.4.5.4..3.2.1.0

Crossrefs

Sequence in context: A279260 A371987 A294471 * A104970 A216727 A174075

Adjacent sequences: A194992 A194993 A194994 * A194996 A194997 A194998

Keyword

nonn

Author

R. H. Hardin Sep 07 2011

Status

approved