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A183644 Number of (n+1) X 2 0..4 arrays with every 2 X 2 subblock summing to 8. 1
85, 325, 1333, 5725, 25405, 115525, 535333, 2517805, 11982925, 57575125, 278766133, 1358125885, 6649985245, 32693825125, 161264049733, 797557733965, 3952911584365, 19625567713525, 97573430562133, 485654176126045 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 1 of A183652.
LINKS
FORMULA
Empirical: a(n) = 15*a(n-1) - 85*a(n-2) + 225*a(n-3) - 274*a(n-4) + 120*a(n-5).
Conjectures from Colin Barker, Mar 31 2018: (Start)
G.f.: x*(85 - 950*x + 3683*x^2 - 5770*x^3 + 3000*x^4) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)*(1 - 5*x)).
a(n) = 2 + 2^(2+n) + 2^(3+2*n) + 2*3^(1+n) + 5^(1+n).
(End)
EXAMPLE
Some solutions for 3 X 2:
4 2 3 1 2 3 3 0 1 4 1 4 0 4 1 3 3 1 1 3
2 0 0 4 0 3 1 4 1 2 2 1 3 1 3 1 1 3 0 4
2 4 1 3 1 4 3 0 2 3 2 3 0 4 1 3 4 0 1 3
CROSSREFS
Cf. A183652.
Sequence in context: A020200 A020298 A183652 * A068559 A045017 A297399
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 06 2011
STATUS
approved

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Last modified June 13 07:36 EDT 2024. Contains 373366 sequences. (Running on oeis4.)