A299556 Number of nX3 0..1 arrays with every element equal to 0, 2, 3, 5, 7 or 8 king-move adjacent elements, with upper left element zero.

1, 7, 5, 15, 21, 57, 121, 289, 747, 1901, 5017, 13531, 36501, 99555, 272873, 748887, 2061111, 5679261, 15657685, 43198325, 119216101, 329067269, 908467521, 2508239639, 6925531875, 19123005315, 52804249441, 145810426239, 402636515557

Offset

1,2

Comments

Column 3 of A299561.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -5*a(n-2) -5*a(n-3) -2*a(n-4) +20*a(n-5) +9*a(n-6) -39*a(n-7) +18*a(n-8) -10*a(n-9) -41*a(n-10) +83*a(n-11) +26*a(n-12) -44*a(n-13) +7*a(n-14) -9*a(n-15) -17*a(n-16) -3*a(n-17) +6*a(n-18) +2*a(n-19) for n>20

Example

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

Crossrefs

Cf. A299561.

Sequence in context: A265818 A046557 A298722 * A282978 A125719 A070975

Adjacent sequences: A299553 A299554 A299555 * A299557 A299558 A299559

Keyword

nonn

Author

R. H. Hardin, Feb 12 2018

Status

approved