A252434 Number of (1+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

641, 915, 1142, 1693, 2710, 4342, 6941, 12295, 20379, 34247, 61505, 105195, 178817, 323844, 556603, 948521, 1716416, 2957030, 5043301, 9112051, 15722010, 26825787, 48379614, 83582702, 142663489, 256824515, 444230495, 758496796, 1363061440

Offset

1,1

Comments

Row 1 of A252433

Links

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

Formula

Empirical: a(n) = 17*a(n-3) -105*a(n-6) +2*a(n-7) +277*a(n-9) -28*a(n-10) -267*a(n-12) +139*a(n-13) -a(n-14) +19*a(n-15) -291*a(n-16) +11*a(n-17) +85*a(n-18) +232*a(n-19) -34*a(n-20) -25*a(n-21) +6*a(n-22) +14*a(n-23) -85*a(n-25) +35*a(n-26) +25*a(n-28) -25*a(n-29) for n>44

Example

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

Crossrefs

Sequence in context: A160203 A251840 A252433 * A105130 A117129 A106488

Adjacent sequences: A252431 A252432 A252433 * A252435 A252436 A252437

Keyword

nonn

Author

R. H. Hardin, Dec 17 2014

Status

approved