A283780 Number of nX4 0..1 arrays with no 1 equal to more than two of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly two elements.

0, 14, 625, 10910, 174447, 2510456, 33933330, 439118692, 5498459845, 67121993862, 802882295057, 9444916323342, 109571555114744, 1256227000217798, 14257060902385365, 160383949024164060, 1790320360619426367

Offset

1,2

Comments

Column 4 of A283784.

Links

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

Formula

Empirical: a(n) = 21*a(n-1) -75*a(n-2) -500*a(n-3) -681*a(n-4) +14070*a(n-5) +66834*a(n-6) +139032*a(n-7) -160275*a(n-8) -1405556*a(n-9) -3401838*a(n-10) -791658*a(n-11) +13175067*a(n-12) +36437481*a(n-13) +23855217*a(n-14) -68703699*a(n-15) -216054840*a(n-16) -171287535*a(n-17) +224531338*a(n-18) +760107903*a(n-19) +595077312*a(n-20) -505895393*a(n-21) -1576187241*a(n-22) -1019970015*a(n-23) +756331656*a(n-24) +1728765105*a(n-25) +791098521*a(n-26) -581764517*a(n-27) -828007422*a(n-28) -234508218*a(n-29) +151749818*a(n-30) +120782574*a(n-31) +37179264*a(n-32) +12003673*a(n-33) -692574*a(n-34) -4660656*a(n-35) -2434512*a(n-36) -906336*a(n-37) -352896*a(n-38) -94208*a(n-39) -17664*a(n-40) -3840*a(n-41) -512*a(n-42)

Example

Some solutions for n=4
..0..0..1..1. .1..1..0..0. .0..0..0..1. .1..1..0..1. .1..1..0..0
..0..1..1..1. .1..1..0..1. .0..0..1..1. .1..0..1..1. .1..1..0..1
..0..1..0..0. .1..0..1..0. .1..1..1..0. .0..0..1..0. .1..1..0..0
..0..0..0..1. .1..0..1..1. .1..0..1..0. .0..1..0..0. .0..0..0..1

Crossrefs

Cf. A283784.

Sequence in context: A209678 A280676 A209103 * A210808 A139196 A336513

Adjacent sequences: A283777 A283778 A283779 * A283781 A283782 A283783

Keyword

nonn

Author

R. H. Hardin, Mar 16 2017

Status

approved