A279979 Number of 3 X n 0..1 arrays with no element equal to a strict majority of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

0, 9, 50, 221, 822, 2669, 8068, 23169, 64250, 173509, 459148, 1195219, 3069280, 7791834, 19587853, 48827241, 120818815, 297018329, 725970958, 1765237102, 4272245780, 10296018246, 24717636634, 59130589267, 140997069400, 335205034089, 794714054209, 1879307452216

Offset

1,2

Comments

Row 3 of A279977.

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -33*a(n-2) +60*a(n-3) -36*a(n-4) -78*a(n-5) +199*a(n-6) -165*a(n-7) -33*a(n-8) +200*a(n-9) -180*a(n-10) +66*a(n-11) +22*a(n-12) -78*a(n-13) +84*a(n-14) -40*a(n-15) -21*a(n-16) +15*a(n-17) -3*a(n-18) +18*a(n-19) +6*a(n-20) -4*a(n-21) -3*a(n-22) -3*a(n-23) -a(n-24) for n>30.

Example

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

Crossrefs

Cf. A279977.

Sequence in context: A280549 A084367 A006974 * A222993 A171480 A369906

Adjacent sequences: A279976 A279977 A279978 * A279980 A279981 A279982

Keyword

nonn

Author

R. H. Hardin, Dec 24 2016

Status

approved