A251899 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum unequal to 4 or 5 and every diagonal and antidiagonal sum equal to 4 or 5

2596, 1548, 1586, 1962, 3910, 6744, 9830, 18590, 34826, 59814, 108694, 195918, 357988, 675680, 1219152, 2210766, 4192704, 7776562, 14201302, 26491586, 49495812, 91788030, 170653566, 317356866, 591342258, 1103205622, 2051539582

Offset

1,1

Comments

Column 2 of A251905

Links

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

Formula

Empirical: a(n) = a(n-1) +a(n-2) +4*a(n-3) +5*a(n-4) -14*a(n-5) -2*a(n-6) -44*a(n-7) +36*a(n-8) +5*a(n-9) +64*a(n-10) +17*a(n-11) -28*a(n-12) -22*a(n-13) -76*a(n-14) +8*a(n-15) +4*a(n-16) +14*a(n-17) +38*a(n-18) +6*a(n-20) -12*a(n-21) -8*a(n-22) +8*a(n-23) -12*a(n-24) +8*a(n-26) for n>33

Example

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

Crossrefs

Sequence in context: A107569 A269287 A204774 * A236598 A237163 A203257

Adjacent sequences: A251896 A251897 A251898 * A251900 A251901 A251902

Keyword

nonn

Author

R. H. Hardin, Dec 10 2014

Status

approved