A232305 Number of nX4 0..2 arrays with every 0 next to a 1 and every 1 next to a 2 horizontally, vertically or antidiagonally

15, 1915, 107047, 6363511, 382995685, 22952606015, 1376103637041, 82507009197797, 4946765617435461, 296587635447682217, 17782170643106187059, 1066145468469096971225, 63921677621500141207283

Offset

1,1

Comments

Column 4 of A232309

Links

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

Formula

Empirical: a(n) = 48*a(n-1) +558*a(n-2) +9275*a(n-3) +9687*a(n-4) +343512*a(n-5) -2285607*a(n-6) +14866055*a(n-7) -181884028*a(n-8) +995697191*a(n-9) -5197173220*a(n-10) +15530478379*a(n-11) -9636101562*a(n-12) -67093411703*a(n-13) +267936483072*a(n-14) -191200540352*a(n-15) -6112388650712*a(n-16) +22237256495440*a(n-17) +63292605427616*a(n-18) -348622165002352*a(n-19) +11398003325440*a(n-20) +1859079636021248*a(n-21) -1555747925062400*a(n-22) -84708377445376*a(n-23) -6207842614584320*a(n-24) +600629890977792*a(n-25) +21168065041268736*a(n-26) -8430208775356416*a(n-27) -26470468634542080*a(n-28) +17291523301310464*a(n-29) +17603417383895040*a(n-30) -12696610521743360*a(n-31) -4661929301770240*a(n-32) +4503599627370496*a(n-33)

Example

Some solutions for n=3
..1..1..0..0....2..1..2..0....1..2..1..1....2..1..1..2....2..1..2..0
..2..1..2..1....0..2..2..1....2..0..2..1....2..1..2..1....2..0..1..1
..0..0..1..0....0..1..0..0....2..1..1..0....0..0..0..0....1..2..0..2

Crossrefs

Sequence in context: A070862 A077730 A110103 * A282946 A319623 A208875

Adjacent sequences: A232302 A232303 A232304 * A232306 A232307 A232308

Keyword

nonn

Author

R. H. Hardin, Nov 22 2013

Status

approved