A303250 Number of nX4 0..1 arrays with every element equal to 1, 2, 3, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

2, 45, 203, 1401, 8664, 55624, 349273, 2229806, 14141138, 89782352, 570414504, 3623364042, 23013173083, 146192778743, 928659809148, 5899066377892, 37473134952091, 238043423305307, 1512137758273339, 9605680030690948

Offset

1,1

Comments

Column 4 of A303254.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) +7*a(n-2) -27*a(n-3) -321*a(n-4) -213*a(n-5) +2807*a(n-6) +3899*a(n-7) -8015*a(n-8) -27255*a(n-9) +12353*a(n-10) +71558*a(n-11) +3162*a(n-12) -120371*a(n-13) +8354*a(n-14) +167215*a(n-15) -138930*a(n-16) -372344*a(n-17) +512518*a(n-18) +604644*a(n-19) -441639*a(n-20) -211921*a(n-21) -765287*a(n-22) +90464*a(n-23) +299277*a(n-24) +209820*a(n-25) +1367674*a(n-26) -1121671*a(n-27) -267827*a(n-28) -130972*a(n-29) -223517*a(n-30) +827606*a(n-31) -782370*a(n-32) -82371*a(n-33) +124045*a(n-34) +68912*a(n-35) +98182*a(n-36) -75028*a(n-37) +2868*a(n-38) +4232*a(n-39) +5296*a(n-40) -864*a(n-41) -1488*a(n-42) +576*a(n-43) for n>44

Example

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

Crossrefs

Cf. A303254.

Sequence in context: A316126 A317432 A302468 * A151583 A325935 A360065

Adjacent sequences: A303247 A303248 A303249 * A303251 A303252 A303253

Keyword

nonn

Author

R. H. Hardin, Apr 20 2018

Status

approved