A206870 Number of nX7 0..1 arrays avoiding 0 0 0 horizontally and 1 0 1 vertically.
81, 6561, 165783, 4108471, 115505069, 3254925997, 90497940567, 2513905109615, 69918135147567, 1945015733467487, 54104019551291657, 1504951979516380911, 41861310528949142861, 1164403984942205341081, 32388853771860099448897
Offset: 1
Keywords
Examples
Some solutions for n=4 ..0..1..1..1..1..0..1....0..1..1..1..0..0..1....1..0..1..1..1..0..0 ..0..1..0..1..1..0..1....0..0..1..0..1..1..0....0..1..0..1..1..0..1 ..1..1..0..0..1..0..1....0..0..1..0..1..1..0....0..1..0..1..0..1..1 ..0..1..1..0..1..1..1....0..1..1..1..0..1..1....0..0..1..1..0..0..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Comments