[go: up one dir, main page]

login
A184033
1/16 the number of (n+1) X 4 0..3 arrays with all 2 X 2 subblocks having the same four values.
2
49, 61, 82, 124, 202, 358, 658, 1258, 2434, 4786, 9442, 18754, 37282, 74338, 148258, 296098, 591394, 1181986, 2362402, 4723234, 9443362, 18883618, 37761058, 75515938, 151019554, 302026786, 604028962, 1208033314, 2416017442, 4831985698
OFFSET
1,1
COMMENTS
Column 3 of A184039.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) - 6*a(n-3) + 4*a(n-4).
Conjectures from Colin Barker, Apr 10 2018: (Start)
G.f.: x*(49 - 86*x - 101*x^2 + 172*x^3) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)).
a(n) = 9*2^(n/2-1) + 9*2^(n-1) + 34 for n even.
a(n) = 9*2^(n-1) + 3*2^((n+1)/2) + 34 for n odd.
(End)
EXAMPLE
Some solutions for 3 X 4:
..0..0..1..2....0..1..0..1....0..2..3..2....2..2..2..2....1..3..1..3
..1..2..0..0....3..2..3..2....3..0..0..0....0..0..0..0....3..2..3..2
..0..0..1..2....1..0..1..0....0..2..3..2....2..2..2..2....1..3..1..3
CROSSREFS
Cf. A184039.
Sequence in context: A039472 A135145 A111327 * A178951 A202001 A038640
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 08 2011
STATUS
approved