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A196134
Number of n X 4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,3,4 for x=0,1,2,3,4.
1
2, 8, 19, 31, 165, 251, 931, 1880, 5556, 15236, 36242, 100659, 238001, 672366, 1720580, 4457811, 11495347, 29435188, 78700799, 203112497, 528285928, 1357620133, 3537680945, 9273276601, 24073315272, 62428922801, 161432508844
OFFSET
1,1
COMMENTS
Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 3's, every 4 is next to 4 4's.
Column 4 of A196138.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-2) +8*a(n-3) +a(n-4) +39*a(n-5) +4*a(n-6) -158*a(n-7) -388*a(n-8) +591*a(n-9) +760*a(n-10) -736*a(n-11) -3520*a(n-12) +2311*a(n-13) +3825*a(n-14) -638*a(n-15) -7762*a(n-16) +9656*a(n-17) +4185*a(n-18) -17112*a(n-19) -4552*a(n-20) +15815*a(n-21) +33775*a(n-22) -23312*a(n-23) -26945*a(n-24) -64119*a(n-25) +139962*a(n-26) +58933*a(n-27) -103605*a(n-28) -338619*a(n-29) +334975*a(n-30) +220898*a(n-31) +159008*a(n-32) -688281*a(n-33) +28868*a(n-34) +145506*a(n-35) +745193*a(n-36) +136204*a(n-37) -163467*a(n-38) -392203*a(n-39) -786507*a(n-40) -198043*a(n-41) +71402*a(n-42) +522504*a(n-43) -893490*a(n-44) -181709*a(n-45) -34798*a(n-46) +1298101*a(n-47) -389417*a(n-48) +272289*a(n-49) -131420*a(n-50) +429738*a(n-51) +86612*a(n-52) -28720*a(n-53) +228880*a(n-54) -528862*a(n-55) +88876*a(n-56) +140772*a(n-57) +250912*a(n-58) -221580*a(n-59) -172620*a(n-60) +248696*a(n-61) +38776*a(n-62) -21376*a(n-63) -9376*a(n-64) +32176*a(n-65) +6752*a(n-66) -42336*a(n-67) +30000*a(n-68) +2976*a(n-69) -12640*a(n-70) -1344*a(n-71) +2880*a(n-72) -768*a(n-73) -384*a(n-74).
EXAMPLE
Some solutions for n=5
..1..2..2..1....0..1..1..1....1..2..2..1....2..1..0..1....0..1..1..0
..0..1..1..0....1..2..2..2....1..1..1..0....1..1..2..2....1..2..2..1
..2..1..1..2....1..0..1..1....2..0..1..2....1..1..1..1....1..2..2..1
..1..1..1..1....2..2..1..1....1..1..1..1....2..2..0..1....1..1..1..1
..1..2..2..1....1..1..1..2....1..2..2..1....1..1..1..2....2..1..1..2
CROSSREFS
Cf. A196138.
Sequence in context: A286263 A236327 A109071 * A256321 A192136 A031327
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 28 2011
STATUS
approved