A302878 Number of 3Xn 0..1 arrays with every element equal to 0, 1, 3, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 6, 17, 35, 72, 241, 722, 1821, 4863, 14841, 43444, 119306, 335624, 985356, 2849009, 8044468, 22928355, 66336411, 190801483, 543986757, 1556622000, 4478561650, 12855871827, 36783013974, 105393294206, 302583744944, 867943015259

Offset

1,1

Comments

Row 3 of A302877.

Links

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

Formula

Empirical: a(n) = a(n-1) +3*a(n-2) +2*a(n-3) +36*a(n-4) -22*a(n-5) -100*a(n-6) -5*a(n-7) -280*a(n-8) +97*a(n-9) +725*a(n-10) -111*a(n-11) +481*a(n-12) -72*a(n-13) -1160*a(n-14) +511*a(n-15) +19*a(n-16) +9*a(n-17) +24*a(n-18) -10*a(n-19) -a(n-20) for n>21

Example

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

Crossrefs

Cf. A302877.

Sequence in context: A337208 A034492 A125691 * A270270 A211949 A079803

Adjacent sequences: A302875 A302876 A302877 * A302879 A302880 A302881

Keyword

nonn

Author

R. H. Hardin, Apr 15 2018

Status

approved