A283637 Number of 4Xn 0..1 arrays with no 1 equal to more than one of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly two elements.

0, 28, 388, 7742, 61592, 700534, 6345928, 54063960, 463390898, 3745175778, 29932577562, 234328588526, 1803842585678, 13723043109600, 103162171803860, 768173607105144, 5671713327162306, 41562268140668656, 302562753480355030

Offset

1,2

Comments

Row 4 of A283634.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +45*a(n-2) -34*a(n-3) -1527*a(n-4) -4200*a(n-5) +5806*a(n-6) +79440*a(n-7) +256035*a(n-8) +556862*a(n-9) +773985*a(n-10) +907686*a(n-11) +67578*a(n-12) -154770*a(n-13) -3028137*a(n-14) -564902*a(n-15) -5353965*a(n-16) +3950340*a(n-17) -4944390*a(n-18) +9675900*a(n-19) -5062575*a(n-20) +8559650*a(n-21) -5818125*a(n-22) +3153750*a(n-23) -3048625*a(n-24) for n>26

Example

Some solutions for n=4
..0..0..1..1. .0..1..0..0. .0..0..0..1. .0..1..1..1. .1..0..1..0
..1..0..0..1. .1..1..0..0. .0..1..0..0. .0..0..0..0. .0..0..1..0
..1..0..0..1. .0..1..0..0. .1..0..0..0. .0..1..1..0. .0..0..0..0
..1..1..0..0. .1..0..0..1. .1..1..0..1. .1..0..1..0. .1..1..1..1

Crossrefs

Cf. A283634.

Sequence in context: A130608 A331353 A177108 * A126921 A035709 A035476

Adjacent sequences: A283634 A283635 A283636 * A283638 A283639 A283640

Keyword

nonn

Author

R. H. Hardin, Mar 12 2017

Status

approved