A211916 T(n,k)=Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any horizontal, vertical, diagonal or antidiagonal neighbor, and containing the value n(n+1)/2-k-1

0, 0, 1, 0, 1, 6, 0, 0, 10, 25, 0, 0, 10, 214, 70, 0, 0, 10, 802, 1946, 156, 0, 0, 10, 1492, 27963, 10431, 301, 0, 0, 0, 1732, 227388, 394117, 40561, 526, 0, 0, 0, 1744, 1085432, 9345480, 3243531, 127275, 855, 0, 0, 0, 1744, 3104732, 146208485, 172044141

Offset

1,6

Comments

Table starts

...0......0........0..........0............0............0.............0

...1......1........0..........0............0............0.............0

...6.....10.......10.........10...........10............0.............0

..25....214......802.......1492.........1732.........1744..........1744

..70...1946....27963.....227388......1085432......3104732.......5535160

.156..10431...394117....9345480....146208485...1546571632...11174140231

.301..40561..3243531..172044141...6410611003.173414544149.3472263194283

.526.127275.18826250.1908272916.140836842878

Links

R. H. Hardin, Table of n, a(n) for n = 1..85

Example

Some solutions for n=4 k=4
..0........0........0........0........0........0........0........0
..1.2......1.2......1.2......1.2......1.2......1.2......1.2......1.2
..0.3.4....3.4.1....3.0.4....3.4.5....3.4.1....3.4.3....3.4.1....3.4.0
..5.6.2.3..0.5.0.4..1.5.3.5..0.1.0.4..0.5.2.6..1.5.0.5..5.2.3.6..1.5.3.6

Crossrefs

Sequence in context: A021866 A258760 A328907 * A037215 A028592 A243254

Adjacent sequences: A211913 A211914 A211915 * A211917 A211918 A211919

Keyword

nonn,tabl

Author

R. H. Hardin Apr 25 2012

Status

approved