A252213 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 2 5 6 or 7

1212, 1078, 1437, 2836, 6674, 17478, 47580, 130032, 357094, 983466, 2708592, 7459998, 20551442, 56618848, 155979808, 429716464, 1183857470, 3261485984, 8985277196, 24754145982, 68196861104, 187880081284, 517603412018

Offset

1,1

Comments

Column 2 of A252219

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = a(n-1) +2*a(n-2) +9*a(n-3) +2*a(n-4) -5*a(n-5) -23*a(n-6) -14*a(n-7) +2*a(n-8) +25*a(n-9) +20*a(n-10) +4*a(n-11) -12*a(n-12) -11*a(n-13) -4*a(n-14) +2*a(n-15) +2*a(n-16) +a(n-17) for n>25

Example

Some solutions for n=4
..3..3..3..2....2..1..1..1....3..2..3..3....1..2..1..1....1..1..1..1
..3..2..3..3....1..1..1..1....3..3..3..2....1..1..1..2....2..1..1..1
..3..3..3..3....1..1..1..1....2..3..3..3....1..1..1..1....1..1..2..1
..2..3..3..3....1..1..1..2....3..3..3..3....1..1..1..1....1..1..1..1
..3..3..3..2....2..1..1..1....3..3..3..3....1..1..1..1....1..1..1..1
..3..2..3..3....1..1..1..1....3..2..3..3....1..1..2..1....1..1..2..1

Crossrefs

Sequence in context: A358711 A138480 A047627 * A258727 A234544 A047626

Adjacent sequences: A252210 A252211 A252212 * A252214 A252215 A252216

Keyword

nonn

Author

R. H. Hardin, Dec 15 2014

Status

approved