A268627 Number of nX7 0..2 arrays with some element plus some horizontally or vertically adjacent neighbor totalling two no more than once.

768, 29646, 982086, 30553014, 915847266, 26758514760, 767057092212, 21665715966234, 604770363515718, 16719464029955466, 458539471622171262, 12491032205839395768, 338309651358216576312, 9117289065936178169226

Offset

1,1

Comments

Column 7 of A268628.

Links

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

Formula

Empirical: a(n) = 110*a(n-1) -5243*a(n-2) +144650*a(n-3) -2610593*a(n-4) +33017408*a(n-5) -305811128*a(n-6) +2137462184*a(n-7) -11513372884*a(n-8) +48502300256*a(n-9) -161412354008*a(n-10) +427044616576*a(n-11) -901108804624*a(n-12) +1517344261024*a(n-13) -2035022988048*a(n-14) +2164824966496*a(n-15) -1815145078160*a(n-16) +1189730382208*a(n-17) -603502277248*a(n-18) +234173991424*a(n-19) -68574152448*a(n-20) +14906358784*a(n-21) -2352277504*a(n-22) +260550656*a(n-23) -19140608*a(n-24) +835584*a(n-25) -16384*a(n-26)

Example

Some solutions for n=2
..0..0..1..0..0..0..1. .1..0..0..1..0..0..0. .0..0..1..0..0..0..2
..0..1..0..0..1..0..1. .0..1..1..2..1..0..1. .0..1..0..0..0..0..1

Crossrefs

Cf. A268628.

Sequence in context: A183687 A269051 A282287 * A170783 A268970 A339763

Adjacent sequences: A268624 A268625 A268626 * A268628 A268629 A268630

Keyword

nonn

Author

R. H. Hardin, Feb 09 2016

Status

approved