A318426 Number of nX4 0..1 arrays with every element unequal to 1, 2, 3 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

2, 50, 147, 889, 3999, 20016, 95349, 461349, 2221254, 10709861, 51624399, 248863408, 1199637700, 5783023852, 27877251865, 134385218809, 647812913270, 3122835963696, 15053866740282, 72568333809069, 349821262874768

Offset

1,1

Comments

Column 4 of A318430.

Links

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

Formula

Empirical: a(n) = a(n-1) +22*a(n-2) +4*a(n-3) -137*a(n-4) +36*a(n-5) +702*a(n-6) +60*a(n-7) -1958*a(n-8) -1039*a(n-9) +2753*a(n-10) +4078*a(n-11) +611*a(n-12) -11794*a(n-13) -27645*a(n-14) +7211*a(n-15) +106409*a(n-16) +65192*a(n-17) -213759*a(n-18) -220752*a(n-19) +236984*a(n-20) +366523*a(n-21) -49842*a(n-22) -353130*a(n-23) -239312*a(n-24) +167419*a(n-25) +307386*a(n-26) +49991*a(n-27) -110369*a(n-28) -187579*a(n-29) -96103*a(n-30) +127637*a(n-31) +137114*a(n-32) +62376*a(n-33) -63709*a(n-34) -95894*a(n-35) -12229*a(n-36) +9328*a(n-37) +32859*a(n-38) +13506*a(n-39) -6729*a(n-40) -3283*a(n-41) -9662*a(n-42) +5992*a(n-43) -1158*a(n-44) +2569*a(n-45) -1800*a(n-46) +510*a(n-47) -323*a(n-48) +200*a(n-49) -59*a(n-50) +19*a(n-51) -7*a(n-52) +a(n-53) for n>59

Example

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

Crossrefs

Cf. A318430.

Sequence in context: A231051 A317819 A231082 * A265962 A318094 A226408

Adjacent sequences: A318423 A318424 A318425 * A318427 A318428 A318429

Keyword

nonn

Author

R. H. Hardin, Aug 26 2018

Status

approved