A254972 Number of (n+2)X(2+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 and no column sum 0

310, 1282, 6915, 27211, 116534, 518534, 2243657, 9685030, 42217091, 183348161, 795467850, 3455917275, 15010520704, 65178568847, 283071522309, 1229382868909, 5338953256844, 23186438236007, 100696512620379, 437311942422531

Offset

1,1

Comments

Column 2 of A254978

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +10*a(n-2) +16*a(n-3) -29*a(n-4) -158*a(n-5) -102*a(n-6) +260*a(n-7) +509*a(n-8) +114*a(n-9) -417*a(n-10) -430*a(n-11) -123*a(n-12) +59*a(n-13) +142*a(n-14) +131*a(n-15) -21*a(n-16) -10*a(n-17) +6*a(n-18) -2*a(n-20) for n>22

Example

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

Crossrefs

Sequence in context: A134549 A304384 A206233 * A237697 A218103 A289304

Adjacent sequences: A254969 A254970 A254971 * A254973 A254974 A254975

Keyword

nonn

Author

R. H. Hardin, Feb 11 2015

Status

approved