A296986 Number of nX4 0..1 arrays with each 1 adjacent to 3, 4 or 5 king-move neighboring 1s.

1, 7, 28, 74, 440, 2514, 12601, 71009, 401521, 2216357, 12389835, 69428069, 387643511, 2166781692, 12118679269, 67747174495, 378749710935, 2117679034553, 11839819553660, 66195424589209, 370099033893829, 2069216112387034

Offset

1,2

Comments

Column 4 of A296990.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +6*a(n-2) +51*a(n-3) -133*a(n-4) -268*a(n-5) -850*a(n-6) +1602*a(n-7) +3436*a(n-8) +6403*a(n-9) -7204*a(n-10) -17827*a(n-11) -31595*a(n-12) +9383*a(n-13) +38828*a(n-14) +93044*a(n-15) +30469*a(n-16) -2987*a(n-17) -173072*a(n-18) -125340*a(n-19) -22415*a(n-20) +291219*a(n-21) +110702*a(n-22) -99668*a(n-23) -406185*a(n-24) -72261*a(n-25) +146112*a(n-26) +278271*a(n-27) +31593*a(n-28) -175355*a(n-29) -108038*a(n-30) -29331*a(n-31) +80234*a(n-32) +31726*a(n-33) -2190*a(n-34) -20309*a(n-35) -7046*a(n-36) +1820*a(n-37) +2688*a(n-38) +739*a(n-39) -55*a(n-40) -103*a(n-41) -24*a(n-42) -3*a(n-43)

Example

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

Crossrefs

Cf. A296990.

Sequence in context: A138503 A223765 A064951 * A211899 A073995 A357694

Adjacent sequences: A296983 A296984 A296985 * A296987 A296988 A296989

Keyword

nonn

Author

R. H. Hardin, Dec 22 2017

Status

approved