A297764 Number of 3 X n 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2, 3 or 4 neighboring 1's.

1, 4, 52, 206, 734, 4088, 24801, 130159, 666434, 3560105, 19245643, 102730864, 546125038, 2913904858, 15571288925, 83122383401, 443489006259, 2366877041892, 12634189755271, 67434790018093, 359910312437155, 1920940558913908

Offset

1,2

Comments

Row 3 of A297762.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -5*a(n-2) +8*a(n-3) +53*a(n-4) -295*a(n-5) -76*a(n-6) +556*a(n-7) +178*a(n-8) +196*a(n-9) +145*a(n-10) -779*a(n-11) -628*a(n-12) +226*a(n-13) +100*a(n-14) +275*a(n-15) +152*a(n-16) -65*a(n-17) -32*a(n-18) -26*a(n-19) -4*a(n-20).

Example

Some solutions for n=7
..0..0..0..0..1..1..0. .0..1..1..1..1..1..0. .0..0..0..0..1..0..0
..1..1..1..0..1..1..1. .0..1..1..1..1..0..1. .0..0..0..1..1..1..0
..0..1..1..1..1..1..0. .0..0..0..0..0..1..0. .0..0..1..1..1..0..0

Crossrefs

Cf. A297762.

Sequence in context: A336428 A298073 A233474 * A101354 A229146 A071953

Adjacent sequences: A297761 A297762 A297763 * A297765 A297766 A297767

Keyword

nonn

Author

R. H. Hardin, Jan 05 2018

Status

approved