A303626 Number of 4Xn 0..1 arrays with every element equal to 0, 2, 3, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

8, 3, 148, 325, 3591, 19467, 160807, 1173612, 9421103, 75073653, 610163560, 4982200456, 40884018586, 336380001790, 2772144413449, 22869613342371, 188783964530800, 1558985724471489, 12877140629903061, 106380021298938000

Offset

1,1

Comments

Row 4 of A303624.

Links

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

Formula

Empirical: a(n) = 16*a(n-1) -39*a(n-2) -486*a(n-3) +2076*a(n-4) +6509*a(n-5) -36557*a(n-6) -51456*a(n-7) +351943*a(n-8) +315012*a(n-9) -2226007*a(n-10) -1747803*a(n-11) +10471115*a(n-12) +7461453*a(n-13) -38373678*a(n-14) -20050380*a(n-15) +107152786*a(n-16) +28648842*a(n-17) -222622519*a(n-18) -3530085*a(n-19) +339517313*a(n-20) -76201625*a(n-21) -361639017*a(n-22) +183843854*a(n-23) +214443094*a(n-24) -255187688*a(n-25) +57118500*a(n-26) +258024061*a(n-27) -306102478*a(n-28) -223408872*a(n-29) +409718455*a(n-30) +187726094*a(n-31) -344439874*a(n-32) -146637084*a(n-33) +189433554*a(n-34) +89003404*a(n-35) -61685576*a(n-36) -35202400*a(n-37) +8565840*a(n-38) +7517168*a(n-39) +603968*a(n-40) -519744*a(n-41) -231936*a(n-42) -40960*a(n-43) for n>44

Example

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

Crossrefs

Cf. A303624.

Sequence in context: A303086 A131502 A302891 * A100253 A175040 A238292

Adjacent sequences: A303623 A303624 A303625 * A303627 A303628 A303629

Keyword

nonn

Author

R. H. Hardin, Apr 27 2018

Status

approved