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A181215 revision #3

A181215

Number of nX4 binary matrices with no three 1's adjacent in a line diagonally or antidiagonally

16, 256, 2500, 28561, 337561, 3857296, 44408896, 512750736, 5909458129, 68121522001, 785456787600, 9055597599504, 104402987257284, 1203692301444361, 13877652596295601, 159998643202876416, 1844662908618342400

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

OFFSET

1,1

COMMENTS

Column 4 of A181217

LINKS

R. H. Hardin, Table of n, a(n) for n=1..225

FORMULA

Empirical: a(n)=11*a(n-1)+16*a(n-2)-24*a(n-3)-906*a(n-4)-2624*a(n-5)+11414*a(n-6)+14042*a(n-7)+444*a(n-8)-92598*a(n-9)-52264*a(n-10)+100166*a(n-11)+77798*a(n-12)-14516*a(n-13)-50238*a(n-14)+950832*a(n-15)-91514*a(n-16)-1551794*a(n-17)-699816*a(n-18)+414094*a(n-19)+1438537*a(n-20)+72931*a(n-21)-647214*a(n-22)+142392*a(n-23)+31008*a(n-24)-44992*a(n-25)+6816*a(n-26)+2496*a(n-27)-256*a(n-28)

EXAMPLE

Some avoided solutions for 3X4

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

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

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

CROSSREFS

Sequence in context: A188905 A189106 A189112 * A223666 A223617 A174335

Adjacent sequences: A181212 A181213 A181214 * A181216 A181217 A181218

KEYWORD

nonn

AUTHOR

R. H. Hardin Oct 10 2010

STATUS

approved