A283660 Number of n X 2 0..1 arrays with no element unequal to more than four of its king-move neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

0, 0, 0, 0, 4, 40, 264, 1504, 7936, 39744, 191552, 896768, 4103616, 18434944, 81563008, 356264448, 1539203584, 6587355136, 27960152064, 117817262080, 493257806848, 2053204985856, 8502296782848, 35043025969152, 143818367385600

Offset

1,5

Links

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

Formula

Empirical: a(n) = 12*a(n-1) - 54*a(n-2) + 124*a(n-3) - 204*a(n-4) + 288*a(n-5) - 248*a(n-6) + 240*a(n-7) - 96*a(n-8) + 64*a(n-9).

Empirical g.f.: 4*x^5*(1 - 2*x) / (1 - 4*x + 2*x^2 - 4*x^3)^3. - Colin Barker, Feb 21 2019

Example

All solutions for n=5:
..0..0. .0..0. .0..0. .0..0
..1..0. .0..1. .1..0. .0..1
..0..0. .0..0. .0..0. .0..0
..0..1. .1..0. .1..0. .0..1
..0..0. .0..0. .0..0. .0..0

Crossrefs

Column 2 of A283666.

Sequence in context: A115286 A119635 A367557 * A215701 A366667 A212699

Adjacent sequences: A283657 A283658 A283659 * A283661 A283662 A283663

Keyword

nonn

Author

R. H. Hardin, Mar 13 2017

Status

approved