A188741 Number of nX3 binary arrays without the pattern 1 1 1 diagonally, vertically or antidiagonally.
8, 64, 292, 1651, 9504, 52072, 289776, 1617326, 8992115, 50039730, 278556885, 1550225927, 8627663414, 48018101493, 267244802833, 1487352476813, 8277889631533, 46070713404315, 256407195751421, 1427038070447781
Offset: 1
Keywords
Examples
Some solutions for 4X3 ..0..0..0....0..0..1....1..0..0....0..0..0....0..1..0....0..0..0....0..1..1 ..0..1..1....1..0..1....0..0..0....0..0..0....0..0..1....0..1..0....0..0..1 ..1..0..0....0..0..0....0..0..1....0..0..1....1..1..0....1..0..0....1..1..0 ..0..0..0....1..1..1....1..0..1....0..1..1....0..1..1....0..0..1....0..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..200
Formula
Empirical: a(n) = 2*a(n-1) +9*a(n-2) +50*a(n-3) +55*a(n-4) +37*a(n-5) -108*a(n-6) -111*a(n-7) +89*a(n-8) +27*a(n-9) -28*a(n-10) -5*a(n-11) -48*a(n-12) -28*a(n-13) -17*a(n-14) -4*a(n-15) -a(n-16)
Comments