A297854 Number of nX4 0..1 arrays with every element equal to 1, 2 or 4 king-move adjacent elements, with upper left element zero.

2, 13, 19, 30, 53, 90, 145, 244, 406, 771, 1396, 2472, 4358, 7688, 13953, 25626, 46458, 83576, 150333, 271566, 494639, 900920, 1633015, 2955455, 5353266, 9717165, 17670119, 32099391, 58228907, 105619960, 191684445, 348131289, 632389497

Offset

1,1

Comments

Column 4 of A297858.

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) +a(n-6) -22*a(n-7) +22*a(n-9) +16*a(n-10) +14*a(n-11) +10*a(n-12) -4*a(n-13) -40*a(n-14) -26*a(n-15) -24*a(n-16) -12*a(n-17) -9*a(n-18) +33*a(n-19) +55*a(n-20) +13*a(n-21) +6*a(n-22) +10*a(n-23) +31*a(n-24) -24*a(n-25) -29*a(n-26) -4*a(n-27) -31*a(n-28) -25*a(n-29) +6*a(n-30) +22*a(n-31) +10*a(n-32) for n>37

Example

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

Crossrefs

Cf. A297858.

Sequence in context: A122139 A122136 A168672 * A298089 A067208 A142348

Adjacent sequences: A297851 A297852 A297853 * A297855 A297856 A297857

Keyword

nonn

Author

R. H. Hardin, Jan 07 2018

Status

approved