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A183640 Number of (n+1) X 8 0..3 arrays with every 2 X 2 subblock summing to 6. 1
79172, 107992, 170300, 309016, 629132, 1398952, 3333500, 8411896, 22294892, 61632712, 176596700, 521681176, 1582485452, 4916663272, 15625379900, 50774508856, 168710304812, 573264314632, 1991498803100, 7067664046936 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 7 of A183642.
LINKS
FORMULA
Empirical: a(n) = 10*a(n-1) - 35*a(n-2) + 50*a(n-3) - 24*a(n-4).
Conjectures from Colin Barker, Mar 31 2018: (Start)
G.f.: 4*x*(19793 - 170932*x + 465350*x^2 - 393216*x^3) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)).
a(n) = 52670 + 3025*2^(2+n) + 254*3^(1+n) + 4^(1+n).
(End)
EXAMPLE
Some solutions for 3 X 8:
2 0 3 0 3 1 3 0 0 3 1 3 1 3 1 3 1 3 1 2 1 1 0 3
2 2 1 2 1 1 1 2 1 2 0 2 0 2 0 2 2 0 2 1 2 2 3 0
2 0 3 0 3 1 3 0 0 3 1 3 1 3 1 3 2 2 2 1 2 0 1 2
CROSSREFS
Cf. A183642.
Sequence in context: A180973 A264950 A204570 * A157661 A159713 A251208
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 06 2011
STATUS
approved

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Last modified June 22 03:16 EDT 2024. Contains 373561 sequences. (Running on oeis4.)