A252579 Number of (5+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 5 6 or 7

2637, 7610, 34532, 88844, 498696, 2538669, 6590930, 37656158, 199331443, 514906002, 2994563004, 16370844276, 42106677118, 248304737187, 1390789570131, 3565907298743, 21240150477364, 121018033333627, 309607017470686

Offset

1,1

Comments

Row 5 of A252574

Links

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

Formula

Empirical: a(n) = 156*a(n-3) -6470*a(n-6) +53472*a(n-9) -284258*a(n-12) +1115672*a(n-15) -1799999*a(n-18) +969878*a(n-21) -48450*a(n-24) for n>32

Example

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

Crossrefs

Sequence in context: A236502 A212605 A273184 * A253040 A157609 A249462

Adjacent sequences: A252576 A252577 A252578 * A252580 A252581 A252582

Keyword

nonn

Author

R. H. Hardin, Dec 18 2014

Status

approved