A255023 Number of (n+2)X(4+2) 0..1 arrays with no 3x3 subblock diagonal sum 0 or 1 and no antidiagonal sum 0 or 1 and no row sum 0 or 1 and no column sum 0 or 1

269, 1121, 5077, 21854, 92217, 391926, 1669286, 7114859, 30309034, 129016023, 549319029, 2339546992, 9963141837, 42425232242, 180661430018, 769335984165, 3276146397830, 13951092432171, 59409215103985, 252988054381890

Offset

1,1

Comments

Column 4 of A255027

Links

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

Formula

Empirical: a(n) = a(n-1) +6*a(n-2) +20*a(n-3) +54*a(n-4) +38*a(n-5) -41*a(n-6) -191*a(n-7) -285*a(n-8) +296*a(n-9) +753*a(n-10) -160*a(n-11) -791*a(n-12) -99*a(n-13) +334*a(n-14) +98*a(n-15) -18*a(n-16) +54*a(n-17) -3*a(n-18) -35*a(n-19) +3*a(n-20) -12*a(n-21) -7*a(n-22) +4*a(n-23) for n>25

Example

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

Crossrefs

Cf. A255027

Sequence in context: A142636 A142385 A142823 * A059330 A054803 A251216

Adjacent sequences: A255020 A255021 A255022 * A255024 A255025 A255026

Keyword

nonn

Author

R. H. Hardin, Feb 13 2015

Status

approved