A197238 Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,3,2,1,2 for x=0,1,2,3,4

1, 8, 46, 231, 1221, 6284, 32754, 170928, 888997, 4628482, 24105642, 125519823, 653563458, 3403159865, 17720701794, 92272812665, 480470439059, 2501848357281, 13027318240407, 67834213566454, 353217871857983, 1839232324012492

Offset

1,2

Comments

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

Column 4 of A197242

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +4*a(n-2) +36*a(n-3) +26*a(n-4) -228*a(n-6) -184*a(n-7) -403*a(n-8) -173*a(n-9) -80*a(n-10) +149*a(n-11) +26*a(n-12) +297*a(n-13) -1359*a(n-14) -769*a(n-15) +2039*a(n-16) +741*a(n-17) -976*a(n-18) +22*a(n-19) +962*a(n-20) +281*a(n-21) -2642*a(n-22) -3738*a(n-23) +689*a(n-24) +4813*a(n-25) +2462*a(n-26) -2068*a(n-27) -1942*a(n-28) +1113*a(n-29) +1865*a(n-30) +372*a(n-31) -577*a(n-32) -416*a(n-33) -64*a(n-34) +44*a(n-35) +24*a(n-36) +4*a(n-37)

Example

Some solutions containing all values 0 to 4 for n=5
..0..2..2..2....1..3..1..0....1..0..0..0....0..1..0..0....0..2..2..2
..0..2..4..2....0..1..0..0....3..1..0..0....1..3..1..0....0..2..4..2
..1..2..2..2....0..2..2..2....1..2..2..2....2..2..2..0....0..2..2..2
..3..1..1..0....0..2..4..2....0..2..4..2....2..4..2..0....1..3..1..0
..1..1..3..1....0..2..2..2....0..2..2..2....2..2..2..0....0..1..0..0

Crossrefs

Sequence in context: A071586 A027650 A172064 * A182542 A026843 A026874

Adjacent sequences: A197235 A197236 A197237 * A197239 A197240 A197241

Keyword

nonn

Author

R. H. Hardin Oct 12 2011

Status

approved