A268890 Number of 5Xn binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

0, 235, 2418, 31956, 317966, 3283890, 31427480, 299524050, 2777161184, 25505113994, 231143340184, 2077724593805, 18526267129268, 164165431218906, 1446558738555296, 12686251671077220, 110791183092125102

Offset

1,2

Comments

Row 5 of A268886.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +97*a(n-2) +116*a(n-3) -2923*a(n-4) -10986*a(n-5) +4951*a(n-6) +72992*a(n-7) +36740*a(n-8) -223968*a(n-9) -159382*a(n-10) +423052*a(n-11) +256370*a(n-12) -539504*a(n-13) -176570*a(n-14) +450908*a(n-15) +6166*a(n-16) -217920*a(n-17) +57416*a(n-18) +45120*a(n-19) -25021*a(n-20) +562*a(n-21) +2089*a(n-22) -388*a(n-23) -31*a(n-24) +14*a(n-25) -a(n-26)

Example

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

Crossrefs

Cf. A268886.

Sequence in context: A129857 A146092 A257310 * A254676 A146126 A264325

Adjacent sequences: A268887 A268888 A268889 * A268891 A268892 A268893

Keyword

nonn

Author

R. H. Hardin, Feb 15 2016

Status

approved