A298142 Number of nX4 0..1 arrays with every element equal to 2, 3, 6 or 7 king-move adjacent elements, with upper left element zero.

0, 1, 2, 8, 13, 27, 43, 104, 220, 478, 988, 2085, 4451, 9505, 20311, 43151, 91982, 195977, 418524, 892675, 1904782, 4063008, 8670687, 18504003, 39492308, 84283520, 179879444, 383917687, 819414074, 1748947386, 3732920854, 7967557278

Offset

1,3

Comments

Column 4 of A298146.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +2*a(n-2) -4*a(n-3) +3*a(n-4) -10*a(n-6) -2*a(n-7) -4*a(n-8) +11*a(n-9) +8*a(n-10) -2*a(n-11) +2*a(n-12) -2*a(n-13) -2*a(n-14) +12*a(n-15) -a(n-16) -6*a(n-17) +a(n-18) -4*a(n-19) +a(n-21) for n>27

Example

Some solutions for n=7
..0..0..0..0. .0..0..1..1. .0..0..1..1. .0..0..0..0. .0..0..0..0
..0..1..1..0. .0..1..0..1. .0..1..0..1. .0..1..1..0. .0..1..1..0
..0..1..0..1. .0..1..0..1. .1..0..1..0. .0..1..0..1. .0..1..0..1
..0..1..0..1. .1..0..1..0. .1..0..1..0. .0..1..0..1. .0..1..0..1
..0..1..0..1. .1..0..1..0. .1..0..1..0. .0..1..0..1. .0..1..0..1
..0..1..0..1. .1..0..0..1. .0..1..0..1. .1..0..0..1. .0..1..1..0
..0..0..1..1. .1..1..1..1. .0..0..1..1. .1..1..1..1. .0..0..0..0

Crossrefs

Cf. A298146.

Sequence in context: A371381 A037382 A297810 * A095825 A106359 A257036

Adjacent sequences: A298139 A298140 A298141 * A298143 A298144 A298145

Keyword

nonn

Author

R. H. Hardin, Jan 13 2018

Status

approved