A196649 Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,4,0,2,1 for x=0,1,2,3,4

3, 23, 76, 391, 1895, 8118, 37661, 172339, 791490, 3631677, 16619517, 76129750, 348810191, 1598275415, 7323187236, 33551912535, 153722248869, 704306601498, 3226924900161, 14784806391213, 67739415602004, 310360945033631

Offset

1,1

Comments

Every 0 is next to 0 3'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 1's

Column 4 of A196653

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +4*a(n-2) +15*a(n-3) +49*a(n-4) +153*a(n-5) +219*a(n-6) +248*a(n-7) +189*a(n-8) -221*a(n-9) -683*a(n-10) -1258*a(n-11) -1587*a(n-12) -1789*a(n-13) -1966*a(n-14) -1966*a(n-15) -2193*a(n-16) -2166*a(n-17) -1860*a(n-18) -1625*a(n-19) -1338*a(n-20) -926*a(n-21) -354*a(n-22) +109*a(n-23) +327*a(n-24) +485*a(n-25) +372*a(n-26) +164*a(n-27) +17*a(n-28) +11*a(n-29) +21*a(n-30) -7*a(n-31) -12*a(n-32) -3*a(n-33) +2*a(n-34)

Example

Some solutions for n=5
..2..0..0..0....0..0..0..0....0..0..0..0....2..0..2..0....2..0..0..0
..0..0..0..2....0..1..2..0....0..2..1..0....0..0..2..0....0..1..2..0
..0..0..0..2....1..4..1..0....0..1..4..1....0..0..2..2....1..4..1..0
..0..0..0..0....0..1..2..0....0..2..1..0....0..0..0..0....0..1..2..0
..0..2..2..0....2..0..0..2....0..0..0..2....0..0..0..2....0..0..0..0

Crossrefs

Sequence in context: A163211 A126335 A256329 * A363170 A357738 A027701

Adjacent sequences: A196646 A196647 A196648 * A196650 A196651 A196652

Keyword

nonn

Author

R. H. Hardin Oct 04 2011

Status

approved