A304468 Number of nX4 0..1 arrays with every element unequal to 0, 1, 2, 3 or 6 king-move adjacent elements, with upper left element zero.

8, 49, 117, 322, 1100, 2957, 8254, 26698, 77788, 221123, 681855, 2041108, 5932703, 17889612, 53854606, 158987996, 475744589, 1430898909, 4260906900, 12733223515, 38231707572, 114317071912, 341873189152, 1025366065205, 3071359996945

Offset

1,1

Comments

Column 4 of A304472.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) -17*a(n-2) +34*a(n-3) -113*a(n-4) +204*a(n-5) -132*a(n-6) +220*a(n-7) -539*a(n-8) +180*a(n-9) +308*a(n-10) +84*a(n-11) -56*a(n-12) -532*a(n-13) +370*a(n-14) -87*a(n-15) +214*a(n-16) -176*a(n-17) +38*a(n-18) -20*a(n-19) +18*a(n-20) -4*a(n-21) for n>25

Example

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

Crossrefs

Cf. A304472.

Sequence in context: A304771 A316514 A352179 * A272713 A316285 A018200

Adjacent sequences: A304465 A304466 A304467 * A304469 A304470 A304471

Keyword

nonn

Author

R. H. Hardin, May 13 2018

Status

approved