A228503 - OEIS

A228503

Number of nX5 binary arrays with top left value 1 and no two ones adjacent horizontally, vertically, diagonally or antidiagonally.

5, 11, 88, 358, 2002, 9528, 49101, 243118, 1228036, 6141239, 30865981, 154742849, 776765183, 3896668986, 19553995645, 98108834263, 492283814664, 2470048647138, 12393793010466, 62186850336292, 312029099308093, 1565635002686314

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 5 of A228506

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +16*a(n-2) +a(n-3) -27*a(n-4) +a(n-5) +4*a(n-6).

Empirical: g.f. -x*(5+x-14*x^2+x^3+2*x^4) / ( -1+2*x+16*x^2+x^3-27*x^4+x^5+4*x^6 ). - R. J. Mathar, Aug 25 2013

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A090518 A057726 A057727 * A128454 A368013 A188514

Adjacent sequences: A228500 A228501 A228502 * A228504 A228505 A228506

KEYWORD

nonn

AUTHOR

R. H. Hardin Aug 23 2013

STATUS

approved