A295375 Number of nX4 0..1 arrays with each 1 horizontally or vertically adjacent to 0, 2 or 4 1s.

8, 48, 278, 1634, 9507, 55643, 325134, 1900380, 11107738, 64922149, 379465246, 2217922765, 12963500193, 75770103923, 442867155601, 2588505603384, 15129505035474, 88430145882513, 516863613785631, 3021005935526290

Offset

1,1

Comments

Column 4 of A295379.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +a(n-2) -10*a(n-3) -8*a(n-4) +30*a(n-5) -155*a(n-6) +161*a(n-7) -111*a(n-8) +29*a(n-9) +18*a(n-10) +263*a(n-11) -294*a(n-12) +267*a(n-13) -52*a(n-14) -4*a(n-15) -83*a(n-16) -42*a(n-17) +41*a(n-18) -62*a(n-19) -16*a(n-20) +18*a(n-21) +17*a(n-22) +3*a(n-23) +a(n-24) -a(n-25)

Example

Some solutions for n=6
..1..0..0..0. .1..0..0..0. .0..0..1..0. .1..0..0..0. .1..0..0..0
..0..1..0..0. .0..0..1..0. .1..0..0..0. .0..0..0..0. .0..1..1..0
..0..0..0..1. .0..0..0..0. .0..0..0..0. .0..0..0..0. .0..1..1..0
..0..0..0..0. .0..1..1..0. .1..0..1..0. .1..0..1..1. .0..0..0..0
..0..0..0..0. .0..1..1..1. .0..1..0..0. .0..0..1..1. .1..1..0..0
..0..1..0..1. .1..0..1..1. .0..0..0..1. .0..1..0..0. .1..1..0..0

Crossrefs

Cf. A295379.

Sequence in context: A006321 A371620 A295047 * A081554 A231109 A079743

Adjacent sequences: A295372 A295373 A295374 * A295376 A295377 A295378

Keyword

nonn

Author

R. H. Hardin, Nov 21 2017

Status

approved