A252552 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 4 6 or 7

1107, 889, 1477, 3084, 7144, 16327, 37430, 88797, 207847, 481879, 1150442, 2708222, 6301644, 15085495, 35585196, 82935199, 198783648, 469314277, 1094651690, 2625103921, 6199987115, 14467168392, 34700770012, 81969284111, 191315257301

Offset

1,1

Comments

Column 2 of A252558

Links

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

Formula

Empirical: a(n) = 41*a(n-3) -642*a(n-6) +4961*a(n-9) -21249*a(n-12) +55203*a(n-15) -94450*a(n-18) +115159*a(n-21) -104947*a(n-24) +71287*a(n-27) -34926*a(n-30) +11911*a(n-33) -2699*a(n-36) +381*a(n-39) -30*a(n-42) +a(n-45) for n>50

Example

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

Crossrefs

Sequence in context: A291616 A291612 A180296 * A295991 A157376 A185501

Adjacent sequences: A252549 A252550 A252551 * A252553 A252554 A252555

Keyword

nonn

Author

R. H. Hardin, Dec 18 2014

Status

approved