A230651 Number of nX7 0..2 white square subarrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value 2-x(i,j)

0, 63, 231, 11745, 90393, 3951657, 31908483, 1374288243, 11150938215, 479621050353, 3893231603781, 167435671598913, 1359174652590399, 58453268091967479, 474501281118252903, 20406595554618417837

Offset

1,2

Comments

Column 7 of A230652

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 390*a(n-2) -14687*a(n-4) +146138*a(n-6) -823339*a(n-8) -2774563*a(n-10) +26807114*a(n-12) -60400888*a(n-14) +106367378*a(n-16) -35490451*a(n-18) -7548040169*a(n-20) +1542760687*a(n-22) +7961883650*a(n-24) +3473400076*a(n-26) +61902164677*a(n-28) +25546220017*a(n-30) +84369583536*a(n-32) +75320917456*a(n-34) +42723111397*a(n-36) -5387877662*a(n-38) +926204972*a(n-40) -121037200*a(n-42) +10124352*a(n-44) +414720*a(n-46) for n>47

Example

Some solutions for n=5
..2..x..2..x..2..x..2....2..x..2..x..2..x..2....0..x..1..x..1..x..2
..x..0..x..2..x..0..x....x..0..x..0..x..0..x....x..2..x..1..x..0..x
..1..x..0..x..0..x..2....2..x..2..x..1..x..2....1..x..0..x..1..x..2
..x..1..x..0..x..0..x....x..1..x..2..x..1..x....x..1..x..0..x..2..x
..1..x..1..x..2..x..2....1..x..0..x..1..x..1....1..x..2..x..0..x..0

Crossrefs

Sequence in context: A097973 A038644 A083079 * A184457 A184449 A158676

Adjacent sequences: A230648 A230649 A230650 * A230652 A230653 A230654

Keyword

nonn

Author

R. H. Hardin, Oct 27 2013

Status

approved