A202903 - OEIS

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A202903

Number of nX5 0..1 arrays with every one equal to some NW, E or S neighbor.

1, 116, 2801, 51068, 993219, 19675348, 387217701, 7615580812, 149865724619, 2949154384500, 58032851189013, 1141964471454924, 22471517834568427, 442193034899247988, 8701443996312218197, 171226425094497967436

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

OFFSET

1,2

LINKS

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

FORMULA

Empirical: a(n) = 32*a(n-1) -333*a(n-2) +2560*a(n-3) -19872*a(n-4) +109088*a(n-5) -473140*a(n-6) +2025472*a(n-7) -6139616*a(n-8) +12558976*a(n-9) -24536512*a(n-10) +33814016*a(n-11) -9896448*a(n-12) -28295168*a(n-13) +78471168*a(n-14) -164626432*a(n-15) +119472128*a(n-16) +89653248*a(n-17) -176947200*a(n-18) +94371840*a(n-19) -18874368*a(n-20) for n>21.

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Column 5 of A202906.

Sequence in context: A238924 A076044 A241941 * A193170 A296360 A035814

Adjacent sequences: A202900 A202901 A202902 * A202904 A202905 A202906

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 25 2011

STATUS

approved