A252529 Number of (n+2) X (5+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 2 3 6 or 7.
778, 706, 1120, 1592, 4420, 7136, 10720, 30752, 49792, 77696, 227584, 369152, 589312, 1746944, 2836480, 4585472, 13680640, 22224896, 36167680, 108265472, 175931392, 287277056, 861405184, 1399980032, 2289958912, 6872367104
Offset: 1
Keywords
Examples
Some solutions for n=4: ..3..1..3..3..1..3..3....2..0..0..2..0..0..2....1..0..1..1..0..1..1 ..2..2..3..2..2..3..2....1..0..1..1..0..1..1....1..1..0..1..1..0..1 ..3..2..2..3..2..2..3....1..1..0..1..1..0..1....3..0..0..3..0..0..2 ..3..1..3..3..0..3..3....2..0..0..3..0..0..2....1..0..1..1..0..1..1 ..2..2..3..2..2..3..2....1..0..1..1..0..1..2....1..1..0..1..1..0..1 ..3..2..2..3..2..2..3....1..1..0..1..1..0..1....2..0..0..3..0..0..3
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Column 5 of A252532.
Formula
Empirical: a(n) = 12*a(n-3) - 32*a(n-6) for n>8.
Empirical g.f.: 2*x*(389 + 353*x + 560*x^2 - 3872*x^3 - 2026*x^4 - 3152*x^5 + 8256*x^6 + 152*x^7) / ((1 - 2*x)*(1 + 2*x + 4*x^2)*(1 - 4*x^3)). - Colin Barker, Dec 04 2018