A196339 Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 1,4,0,2,3 for x=0,1,2,3,4

3, 23, 88, 495, 2223, 10854, 53647, 262013, 1280764, 6254945, 30578633, 149503874, 730808203, 3572316883, 17462371522, 85361430021, 417272087661, 2039743998384, 9970847387767, 48740355602949, 238256829183690, 1164667576556219

Offset

1,1

Comments

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

Column 4 of A196343

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +7*a(n-2) +21*a(n-3) +56*a(n-4) +84*a(n-5) -35*a(n-6) -304*a(n-7) -675*a(n-8) -1177*a(n-9) -936*a(n-10) +247*a(n-11) +1040*a(n-12) +616*a(n-13) -301*a(n-14) -617*a(n-15) -204*a(n-16) +999*a(n-17) +2210*a(n-18) +1973*a(n-19) +68*a(n-20) -1440*a(n-21) -1074*a(n-22) -47*a(n-23) +267*a(n-24) +42*a(n-25) -22*a(n-26) +35*a(n-27) +17*a(n-28) -14*a(n-29) -3*a(n-30) +2*a(n-31)

Example

Some solutions for n=5
..0..0..0..0....0..0..0..2....0..0..0..0....0..2..0..2....2..0..0..0
..0..0..0..0....0..2..2..0....0..0..0..0....0..2..0..0....0..0..0..0
..0..0..0..0....2..3..3..2....0..0..0..0....0..2..2..2....2..2..0..0
..0..0..2..2....0..2..2..0....2..2..2..0....0..0..0..0....0..2..2..2
..2..0..2..0....0..0..0..2....0..0..2..0....0..0..0..2....0..0..0..0

Crossrefs

Sequence in context: A032017 A197453 A024196 * A196318 A213846 A301580

Adjacent sequences: A196336 A196337 A196338 * A196340 A196341 A196342

Keyword

nonn

Author

R. H. Hardin Oct 01 2011

Status

approved