A207680 Number of nX6 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 1 1 vertically.
19, 361, 702, 2132, 5704, 11994, 25076, 52632, 109811, 215506, 431270, 856818, 1671738, 3290063, 6359426, 12365486, 23939738, 45966515, 88735852, 170028536, 325975917, 624553353, 1192281784, 2279867642, 4348061061, 8290055552
Offset: 1
Keywords
Examples
Some solutions for n=4 ..0..0..1..0..0..1....1..1..1..1..1..1....0..1..1..0..0..1....0..0..1..1..1..1 ..1..0..0..1..1..1....0..1..0..0..1..0....1..1..0..0..1..0....1..0..0..1..0..0 ..0..0..1..1..0..0....1..0..0..1..0..0....0..0..1..0..0..1....0..0..1..0..0..1 ..0..0..1..0..0..1....1..0..0..1..1..0....0..0..1..0..0..1....1..0..0..1..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = a(n-1) +4*a(n-2) +10*a(n-3) -17*a(n-4) -36*a(n-5) -56*a(n-6) +93*a(n-7) +172*a(n-8) +247*a(n-9) -280*a(n-10) -538*a(n-11) -793*a(n-12) +506*a(n-13) +1147*a(n-14) +1793*a(n-15) -488*a(n-16) -1764*a(n-17) -2886*a(n-18) -9*a(n-19) +2098*a(n-20) +3325*a(n-21) +837*a(n-22) -2053*a(n-23) -2784*a(n-24) -1426*a(n-25) +1663*a(n-26) +1753*a(n-27) +1358*a(n-28) -1076*a(n-29) -863*a(n-30) -854*a(n-31) +547*a(n-32) +339*a(n-33) +366*a(n-34) -217*a(n-35) -103*a(n-36) -102*a(n-37) +64*a(n-38) +21*a(n-39) +16*a(n-40) -12*a(n-41) -2*a(n-42) -a(n-43) +a(n-44) for n>51
Comments