A197608 Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,2,1,1,1 for x=0,1,2,3,4

2, 14, 67, 366, 1840, 9361, 47610, 242254, 1234052, 6286646, 32024913, 163120939, 830844663, 4231926412, 21555688607, 109796116924, 559256572765, 2848618914380, 14509668521473, 73906186682768, 376447321305343

Offset

1,1

Comments

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

Column 3 of A197613

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +6*a(n-2) +26*a(n-3) +53*a(n-4) +232*a(n-5) +501*a(n-6) +551*a(n-7) -245*a(n-8) -2023*a(n-9) -3810*a(n-10) -8322*a(n-11) -13685*a(n-12) -22140*a(n-13) -25568*a(n-14) -31943*a(n-15) -6603*a(n-16) +38551*a(n-17) +60843*a(n-18) +53444*a(n-19) +38044*a(n-20) +14221*a(n-21) +7417*a(n-22) +70469*a(n-23) +71386*a(n-24) +16860*a(n-25) +14396*a(n-26) +8246*a(n-27) +5868*a(n-28) +2756*a(n-29) +716*a(n-30) +240*a(n-31) +48*a(n-32)

Example

Some solutions for n=4
..1..1..0....2..1..0....1..1..2....1..2..0....0..0..1....2..1..0....0..0..0
..2..2..0....1..1..2....2..1..1....3..1..0....0..0..2....1..0..0....0..1..0
..1..1..0....0..0..1....0..0..1....1..1..2....0..0..1....0..1..0....1..2..0
..0..0..0....0..0..0....0..1..2....2..1..1....1..2..1....1..2..0....0..0..0

Crossrefs

Sequence in context: A197162 A109869 A197777 * A354048 A325925 A084132

Adjacent sequences: A197605 A197606 A197607 * A197609 A197610 A197611

Keyword

nonn

Author

R. H. Hardin Oct 16 2011

Status

approved