A252435 Number of (2+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 4 6 or 7

602, 688, 1033, 1488, 3057, 6178, 10309, 24196, 50228, 86037, 205258, 426516, 741942, 1784080, 3703542, 6529800, 15796578, 32752826, 58451265, 142157308, 294436272, 531079333, 1297598958, 2685147364, 4887498982, 11988550720

Offset

1,1

Comments

Row 2 of A252433

Links

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

Formula

Empirical: a(n) = 25*a(n-3) -210*a(n-6) +606*a(n-9) +32*a(n-12) -1188*a(n-15) +594*a(n-18) +482*a(n-21) -415*a(n-24) +75*a(n-27) for n>34

Example

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

Crossrefs

Sequence in context: A218055 A045940 A124057 * A363830 A045941 A268588

Adjacent sequences: A252432 A252433 A252434 * A252436 A252437 A252438

Keyword

nonn

Author

R. H. Hardin, Dec 17 2014

Status

approved