A297547 Number of 4Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 or 3 neighboring 1s.

1, 7, 88, 275, 1233, 10234, 65363, 355573, 2194764, 14070932, 85652323, 519260961, 3211470573, 19819925799, 121490746063, 746218947635, 4593161224590, 28240298397593, 173532774710365, 1066882947565281, 6559955677759270

Offset

1,2

Comments

Row 4 of A297544.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -3*a(n-2) +44*a(n-3) -8*a(n-4) -760*a(n-5) +184*a(n-6) +754*a(n-7) -472*a(n-8) +9851*a(n-9) -3362*a(n-10) -5462*a(n-11) +15065*a(n-12) -44830*a(n-13) +67977*a(n-14) +31770*a(n-15) -136673*a(n-16) +48047*a(n-17) +136434*a(n-18) -8657*a(n-19) -324506*a(n-20) -148114*a(n-21) +447636*a(n-22) +20461*a(n-23) -583095*a(n-24) +51345*a(n-25) +442917*a(n-26) +278081*a(n-27) -330620*a(n-28) -659693*a(n-29) +540813*a(n-30) +547243*a(n-31) -369875*a(n-32) -109458*a(n-33) +121844*a(n-34) -54623*a(n-35) -24091*a(n-36) +22529*a(n-37) -4106*a(n-38) -6008*a(n-39) -768*a(n-40)

Example

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

Crossrefs

Cf. A297544.

Sequence in context: A034219 A034238 A132486 * A183486 A372732 A155465

Adjacent sequences: A297544 A297545 A297546 * A297548 A297549 A297550

Keyword

nonn

Author

R. H. Hardin, Dec 31 2017

Status

approved