A252576 Number of (2+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 5 6 or 7.
742, 868, 1795, 3441, 8980, 23007, 47737, 133142, 358343, 747913, 2133162, 5930143, 12407892, 35927539, 102193578, 214180250, 626625460, 1809891284, 3797310562, 11184658108, 32620331477, 68486288857, 202566746459, 594329457551
Offset: 1
Keywords
Examples
Some solutions for n=4 ..2..0..0..1..0..1....2..0..0..1..1..0....0..0..1..1..0..1....3..1..2..3..2..2 ..1..3..2..2..3..2....0..1..0..0..1..1....1..0..0..1..0..1....0..2..0..0..2..0 ..1..0..1..0..0..1....2..2..3..2..2..3....2..3..2..2..3..1....0..0..2..0..0..1 ..1..0..0..2..0..0....2..0..0..1..0..0....1..0..1..0..0..1....3..2..1..3..1..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 42*a(n-3) -595*a(n-6) +3251*a(n-9) -5703*a(n-12) +8191*a(n-15) -8486*a(n-18) +5741*a(n-21) -3340*a(n-24) +900*a(n-27) for n>34
Comments