A252634 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 3 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 3 4 6 or 7

1013, 1684, 4226, 10259, 28978, 80304, 205127, 598762, 1716412, 4519719, 13417956, 39097862, 105011019, 314153189, 922196750, 2510126192, 7536314876, 22192510619, 60965404095, 183344920544, 540553448514, 1494708572659

Offset

1,1

Comments

Column 2 of A252640

Links

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

Formula

Empirical: a(n) = 70*a(n-3) -1858*a(n-6) +23748*a(n-9) -154484*a(n-12) +505834*a(n-15) -868331*a(n-18) +1055614*a(n-21) -1024560*a(n-24) +324000*a(n-27) for n>36

Example

Some solutions for n=4
..1..3..3..1....2..0..2..2....3..3..1..3....3..1..3..0....1..3..2..2
..2..3..2..2....3..3..1..0....2..1..1..2....2..2..0..2....0..3..1..3
..2..2..0..2....3..2..2..3....3..1..3..3....3..2..2..3....0..2..2..0
..1..0..3..1....2..3..2..2....0..3..1..3....3..1..3..0....2..3..2..2
..2..0..2..2....3..3..1..3....2..1..1..2....2..2..3..2....3..0..1..3
..2..2..3..2....3..2..2..3....3..1..3..3....0..2..2..0....0..2..2..3

Crossrefs

Sequence in context: A069489 A157008 A161404 * A250610 A126239 A120214

Adjacent sequences: A252631 A252632 A252633 * A252635 A252636 A252637

Keyword

nonn

Author

R. H. Hardin, Dec 19 2014

Status

approved