A252161 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 2 3 4 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 2 3 4 6 or 7

3712, 1930, 1574, 2075, 3749, 6883, 12842, 26127, 53376, 107547, 227592, 478345, 987231, 2115771, 4499673, 9415660, 20325117, 43552188, 92035081, 199645934, 430071873, 915400011, 1992467987, 4308311421, 9218109146, 20111437177

Offset

1,1

Comments

Column 2 of A252167

Links

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

Formula

Empirical: a(n) = 2*a(n-1) -a(n-2) +24*a(n-3) -43*a(n-4) +19*a(n-5) -204*a(n-6) +296*a(n-7) -98*a(n-8) +790*a(n-9) -738*a(n-10) +74*a(n-11) -1631*a(n-12) +634*a(n-13) +163*a(n-14) +1958*a(n-15) +201*a(n-16) -173*a(n-17) -1451*a(n-18) -698*a(n-19) -11*a(n-20) +672*a(n-21) +583*a(n-22) +41*a(n-23) -60*a(n-24) -416*a(n-25) -22*a(n-26) -310*a(n-27) +162*a(n-28) +94*a(n-29) +323*a(n-30) +182*a(n-31) -31*a(n-32) -110*a(n-33) -165*a(n-34) -55*a(n-35) for n>42

Example

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

Crossrefs

Sequence in context: A234186 A179623 A263035 * A180396 A158917 A252421

Adjacent sequences: A252158 A252159 A252160 * A252162 A252163 A252164

Keyword

nonn

Author

R. H. Hardin, Dec 14 2014

Status

approved