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
Keywords
Examples
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
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A279977.
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.
Comments