A255776 - OEIS

A255776

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

140, 436, 1512, 5126, 17325, 58707, 198635, 672183, 2274999, 7699081, 26056081, 88181805, 298433705, 1009989977, 3418112157, 11567925109, 39149360907, 132493286347, 448397385023, 1517512474487, 5135721548305, 17380836236957

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OFFSET

1,1

COMMENTS

Column 1 of A255783

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +4*a(n-2) +3*a(n-3) +a(n-4) -7*a(n-5) -6*a(n-6) -20*a(n-7) -16*a(n-8) -25*a(n-9) -25*a(n-10) -20*a(n-11) -21*a(n-12) -7*a(n-13) -6*a(n-14) +4*a(n-15) +4*a(n-16) +4*a(n-17) +2*a(n-18)

EXAMPLE

Some solutions for n=4

..0..1..0....1..0..1....1..0..1....1..1..1....1..1..1....1..1..1....1..0..1

..0..1..1....1..1..1....0..1..1....0..1..1....1..1..1....1..0..0....1..1..1

..1..1..1....1..1..1....0..1..1....1..1..1....1..1..1....1..1..1....0..1..1

..0..1..1....1..1..1....1..1..1....0..1..1....1..1..1....1..1..1....1..1..1

..1..1..0....0..1..1....1..1..1....1..1..1....0..1..0....0..1..0....1..1..1

..1..1..1....0..0..1....0..1..1....0..0..1....1..0..0....1..1..0....1..0..1

CROSSREFS

Cf. A255783

Sequence in context: A249554 A196447 A255783 * A242319 A010080 A350210

Adjacent sequences: A255773 A255774 A255775 * A255777 A255778 A255779

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 06 2015

STATUS

approved