A298089 Number of nX4 0..1 arrays with every element equal to 1, 2, 4 or 7 king-move adjacent elements, with upper left element zero.

2, 13, 19, 30, 53, 92, 149, 250, 426, 809, 1456, 2602, 4606, 8096, 14731, 27112, 49118, 88604, 159685, 288458, 526293, 960108, 1742179, 3159153, 5731030, 10414879, 18970871, 34518779, 62715041, 113954032, 207132787, 376765957, 685570021

Offset

1,1

Comments

Column 4 of A298093.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +a(n-2) -a(n-3) -2*a(n-4) +2*a(n-5) +4*a(n-6) -28*a(n-7) -3*a(n-8) +26*a(n-9) +22*a(n-10) +6*a(n-11) +7*a(n-12) +53*a(n-13) -42*a(n-14) -84*a(n-15) -64*a(n-16) -24*a(n-17) -3*a(n-18) +40*a(n-19) +101*a(n-20) +36*a(n-21) +51*a(n-22) +23*a(n-23) +75*a(n-24) -85*a(n-25) -129*a(n-26) +23*a(n-27) +6*a(n-28) -58*a(n-29) -108*a(n-30) +41*a(n-31) +87*a(n-32) +38*a(n-33) -2*a(n-34) -10*a(n-35) for n>40

Example

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

Crossrefs

Cf. A298093.

Sequence in context: A122136 A168672 A297854 * A067208 A142348 A309663

Adjacent sequences: A298086 A298087 A298088 * A298090 A298091 A298092

Keyword

nonn

Author

R. H. Hardin, Jan 12 2018

Status

approved