A197498 - OEIS

A197498

Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,3,1,1,0 for x=0,1,2,3,4

1, 9, 22, 53, 162, 526, 1605, 5011, 15073, 46562, 143487, 440836, 1353988, 4162099, 12795741, 39330623, 120882310, 371559669, 1142099870, 3510484802, 10790188695, 33166049781, 101943428843, 313345715556, 963137000727, 2960415365620

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OFFSET

1,2

COMMENTS

Every 0 is next to 0 2's, every 1 is next to 1 3's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 0's

Column 3 of A197503

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n) = a(n-1) +2*a(n-2) +7*a(n-3) +15*a(n-4) +15*a(n-5) +6*a(n-6) -9*a(n-7) -14*a(n-8) -46*a(n-9) -63*a(n-10) +3*a(n-11) +a(n-12) +39*a(n-13) -16*a(n-14) +39*a(n-15) +27*a(n-16) +32*a(n-17) -3*a(n-18) -11*a(n-19) -14*a(n-20) -8*a(n-21)

EXAMPLE

Some solutions for n=4

..0..0..1....0..0..1....2..1..2....0..1..2....0..0..0....0..0..0....1..3..1

..0..1..3....0..1..3....1..3..1....1..3..1....0..0..0....0..1..0....2..1..2

..0..1..1....0..0..1....0..0..0....1..3..1....1..3..1....0..3..1....2..1..2

..1..3..1....0..0..0....0..0..0....0..1..2....0..1..0....0..1..2....1..3..1

CROSSREFS

Sequence in context: A323221 A250730 A251285 * A287497 A232024 A327150

Adjacent sequences: A197495 A197496 A197497 * A197499 A197500 A197501

KEYWORD

nonn

AUTHOR

R. H. Hardin Oct 15 2011

STATUS

approved