|
|
A251368
|
|
Number of (n+1) X (3+1) 0..2 arrays with every 2 X 2 subblock summing to 1 2 3 4 5 6 or 7.
|
|
1
|
|
|
6113, 464393, 35257505, 2676962017, 203249994369, 15431888950873, 1171676222709377, 88960280954218353, 6754367316602393761, 512829741092571856681, 38936932361040303524065, 2956311969073264569680513
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = 66*a(n-1) + 746*a(n-2) + 660*a(n-3) - 6281*a(n-4) + 3690*a(n-5).
Empirical g.f.: x*(6113 + 60935*x + 47269*x^2 - 505071*x^3 + 298890*x^4) / (1 - 66*x - 746*x^2 - 660*x^3 + 6281*x^4 - 3690*x^5). - Colin Barker, Nov 29 2018
|
|
EXAMPLE
|
Some solutions for n=1:
..1..1..0..0....2..2..0..0....0..2..0..2....2..1..1..1....2..0..1..0
..2..2..2..1....2..0..1..1....1..0..0..0....1..1..1..2....2..0..0..2
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|