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A264203
Number of (n+1) X (3+1) arrays of permutations of 0..n*4+3 with each element having index change +-(.,.) 0,0 0,2 or 1,0.
1
81, 1024, 14641, 202500, 2825761, 39337984, 547981281, 7632119044, 106302733681, 1480602240000, 20622143227921, 287229348456964, 4000588938543681, 55721015032152064, 776093624344221121, 10809589715215402500
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 11*a(n-1) + 44*a(n-2) - 44*a(n-3) - 11*a(n-4) + a(n-5).
Empirical g.f.: x*(81 + 133*x - 187*x^2 - 43*x^3 + 4*x^4) / ((1 - x)*(1 - 14*x + x^2)*(1 + 4*x + x^2)). - Colin Barker, Jan 05 2019
EXAMPLE
Some solutions for n=3:
..0..3..2..7....4..3..0..1....4..5..2..7....0..3..2..1....4..3..6..1
..6..1..4..5....6..9..2.11....0..1..6..3....6..7..4.11....0..5..2.11
..8..9.10.11...12..5.10..7....8.13.10.15...12..5.14..9...10.13.14..7
.12.13.14.15....8.15.14.13...12..9.14.11....8.13.10.15....8..9.12.15
CROSSREFS
Column 3 of A264207.
Sequence in context: A237226 A237159 A183807 * A236047 A264000 A236781
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 08 2015
STATUS
approved