A252570 Number of (n+2)X(4+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

1694, 3441, 9051, 25882, 88844, 263046, 802760, 2655311, 7860183, 24273030, 79767276, 236117012, 730342433, 2398390660, 7098703610, 21963448780, 72127785139, 213445574577, 660482900457, 2169282202310, 6418274172794

Offset

1,1

Comments

Column 4 of A252574

Links

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

Formula

Empirical: a(n) = 82*a(n-3) -2429*a(n-6) +33486*a(n-9) -261118*a(n-12) +1295078*a(n-15) -4396152*a(n-18) +10604184*a(n-21) -18276440*a(n-24) +22254797*a(n-27) -19021565*a(n-30) +11461650*a(n-33) -4926134*a(n-36) +1526628*a(n-39) -338818*a(n-42) +51264*a(n-45) -4731*a(n-48) +223*a(n-51) -4*a(n-54) for n>60

Example

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

Crossrefs

Sequence in context: A366644 A325884 A224605 * A235182 A237170 A301985

Adjacent sequences: A252567 A252568 A252569 * A252571 A252572 A252573

Keyword

nonn

Author

R. H. Hardin, Dec 18 2014

Status

approved