A252533 Number of (1+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 3 6 or 7.
750, 730, 621, 719, 778, 932, 1200, 1498, 1968, 2708, 3473, 4698, 6444, 8494, 11435, 15560, 20630, 27462, 36761, 48910, 64407, 85224, 113390, 148048, 193940, 258080, 334681, 435134, 578923, 746716, 964795, 1283490, 1648229, 2118894, 2818420
Offset: 1
Keywords
Examples
Some solutions for n=4 ..2..2..2..3..1..3....3..1..3..3..1..3....3..3..0..0..0..3....1..1..0..1..1..0 ..2..1..0..1..1..0....2..2..3..2..2..3....3..2..2..3..1..3....3..0..0..3..0..3 ..1..2..3..1..3..2....3..2..2..3..1..2....2..3..2..1..3..2....1..0..1..1..0..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 4*a(n-3) -3*a(n-6) -4*a(n-9) +4*a(n-12) for n>39
Comments