A207727 Number of nX6 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 1 and 1 0 1 vertically.
25, 625, 2209, 10609, 60025, 277729, 1247689, 5890329, 27426169, 125776225, 580858201, 2686867225, 12388803025, 57136775089, 263724358681, 1216770043329, 5612971227241, 25896730187689, 119479087561201, 551206670239681
Offset: 1
Keywords
Examples
Some solutions for n=4 ..1..1..1..1..0..1....0..0..1..1..0..1....0..1..1..1..1..0....0..0..1..1..0..0 ..1..1..1..1..1..1....1..1..1..1..0..0....1..1..1..1..1..1....1..0..1..1..1..1 ..1..1..1..0..0..1....0..0..1..1..0..0....0..0..1..1..0..0....0..0..1..1..0..0 ..1..1..1..0..0..1....0..0..1..1..0..0....0..0..1..1..0..0....0..1..1..1..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 6*a(n-1) -7*a(n-2) +31*a(n-3) -128*a(n-4) -30*a(n-5) -116*a(n-6) +788*a(n-7) +798*a(n-8) +678*a(n-9) -2778*a(n-10) -1872*a(n-11) -1842*a(n-12) +3336*a(n-13) +1554*a(n-14) +378*a(n-15) -2736*a(n-16) +912*a(n-17) +312*a(n-18) +1590*a(n-19) -540*a(n-20) -228*a(n-21) -222*a(n-22) +210*a(n-23) -86*a(n-24) +24*a(n-25) -38*a(n-26) +8*a(n-27) -a(n-28) -a(n-30) +a(n-31)
Comments