A251900 Number of (n+2)X(3+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

3312, 1586, 1536, 2772, 6408, 10662, 16848, 35992, 68496, 124364, 245836, 470306, 910476, 1826136, 3521588, 6889776, 13879176, 27307258, 53819940, 107870152, 214245840, 425563680, 851234568, 1695933986, 3381382444, 6763588448

Offset

1,1

Comments

Column 3 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) +a(n-3) +9*a(n-4) -7*a(n-5) +13*a(n-6) -27*a(n-7) -39*a(n-8) -15*a(n-9) -152*a(n-10) +122*a(n-11) +52*a(n-12) +192*a(n-13) +394*a(n-14) -10*a(n-15) +199*a(n-16) -219*a(n-17) -232*a(n-18) -206*a(n-19) -460*a(n-20) +48*a(n-21) +24*a(n-22) +72*a(n-23) +192*a(n-24) -48*a(n-25) -96*a(n-26) for n>30

Example

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

Crossrefs

Sequence in context: A239671 A181559 A180679 * A078348 A078963 A236643

Adjacent sequences: A251897 A251898 A251899 * A251901 A251902 A251903

Keyword

nonn

Author

R. H. Hardin, Dec 10 2014

Status

approved