A303471 Number of 4Xn 0..1 arrays with every element equal to 0, 1, 2, 3, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

8, 128, 1033, 9110, 79377, 692636, 6051850, 52846843, 461529362, 4030762937, 35202137794, 307434409358, 2684948462398, 23448727446524, 204787130200395, 1788488024787439, 15619582094687097, 136412065575277095

Offset

1,1

Comments

Row 4 of A303469.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) +46*a(n-2) -45*a(n-3) -626*a(n-4) -454*a(n-5) +3362*a(n-6) +4834*a(n-7) -11974*a(n-8) -5100*a(n-9) +76824*a(n-10) +1064*a(n-11) -279364*a(n-12) -234634*a(n-13) -123891*a(n-14) +61518*a(n-15) +1304955*a(n-16) +1781392*a(n-17) +1362613*a(n-18) +3046799*a(n-19) +2392659*a(n-20) -3703363*a(n-21) -10637854*a(n-22) -16594164*a(n-23) -15747787*a(n-24) +1164554*a(n-25) +14083230*a(n-26) -2759852*a(n-27) -8828997*a(n-28) +23505494*a(n-29) +52936752*a(n-30) +54496267*a(n-31) +18062511*a(n-32) -48471125*a(n-33) -74206110*a(n-34) -23203749*a(n-35) +31338125*a(n-36) +28388603*a(n-37) -334667*a(n-38) -9249716*a(n-39) -2429504*a(n-40) +1208431*a(n-41) +521125*a(n-42) -3517*a(n-43) -5211*a(n-44) -12425*a(n-45) -6830*a(n-46) +132*a(n-47) +481*a(n-48) +48*a(n-49) for n>50

Example

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

Crossrefs

Cf. A303469.

Sequence in context: A301822 A302810 A061549 * A301998 A105094 A208711

Adjacent sequences: A303468 A303469 A303470 * A303472 A303473 A303474

Keyword

nonn

Author

R. H. Hardin, Apr 24 2018

Status

approved