[go: up one dir, main page]

login
A196969
Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,3,0,2,1 for x=0,1,2,3,4
1
2, 10, 34, 104, 386, 1380, 4800, 16794, 58875, 206084, 721260, 2525126, 8840855, 30952194, 108366098, 379400544, 1328316102, 4650549495, 16281977271, 57004611828, 199578061611, 698740003512, 2446349057586, 8564879222176
OFFSET
1,1
COMMENTS
Every 0 is next to 0 4's, every 1 is next to 1 3'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 3 of A196974
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +5*a(n-2) +2*a(n-3) -2*a(n-4) -11*a(n-5) +a(n-6) +36*a(n-7) +50*a(n-8) +20*a(n-9) -20*a(n-10) -49*a(n-11) -42*a(n-12) -20*a(n-13) +4*a(n-14) +9*a(n-15) +2*a(n-16)
EXAMPLE
Some solutions for n=4
..0..2..0....0..0..0....2..0..0....0..0..2....0..0..2....0..2..0....0..0..2
..2..3..2....2..3..2....0..2..2....0..0..0....2..2..0....0..2..2....2..2..0
..0..0..0....0..2..0....2..3..0....2..2..0....0..3..2....0..0..0....0..2..0
..0..0..0....0..2..0....0..2..0....0..2..0....0..2..0....0..0..2....0..2..0
CROSSREFS
Sequence in context: A022498 A036799 A190161 * A351551 A351550 A119193
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 08 2011
STATUS
approved