A207510 Number of nX4 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 1 1 vertically.
9, 81, 166, 438, 1042, 1992, 4168, 8174, 15881, 30801, 58335, 111083, 209072, 391336, 731541, 1358864, 2519079, 4655423, 8579122, 15779179, 28954160, 53037211, 96982948, 177063128, 322816525, 587759306, 1068885187, 1941639552, 3523372673
Offset: 1
Keywords
Examples
Some solutions for n=4 ..1..1..0..0....1..0..0..1....1..1..0..1....1..1..0..1....1..1..0..0 ..1..1..1..1....0..1..0..0....1..1..1..1....1..0..0..1....0..0..1..0 ..0..0..1..0....1..1..0..1....0..0..1..0....0..1..0..0....0..1..0..0 ..0..1..0..0....1..0..0..1....0..1..0..0....0..1..0..1....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) +14*a(n-3) +5*a(n-4) -31*a(n-5) -67*a(n-6) -28*a(n-7) +76*a(n-8) +171*a(n-9) +113*a(n-10) -61*a(n-11) -229*a(n-12) -197*a(n-13) -27*a(n-14) +154*a(n-15) +175*a(n-16) +71*a(n-17) -46*a(n-18) -89*a(n-19) -45*a(n-20) -6*a(n-21) +32*a(n-22) +12*a(n-23) +10*a(n-24) -7*a(n-25) -a(n-26) -2*a(n-27) +a(n-28) for n>32
Comments