OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..112
N. H. Bong, C. Dalfó, and M. À. Fiol, and D. Závacká, Some inner metric parameters of a digraph: Iterated line digraphs and integer sequences, arXiv:2409.02125 [math.CO], 2024. See p. 19.
FORMULA
Empirical for column k:
k=1: a(n) = 2*a(n-1) +2*a(n-2)
k=2: [order 19]
k=3: [order 67]
Empirical for row n:
n=1: a(n) = 4*a(n-1) -a(n-2) +3*a(n-3) +3*a(n-4) -4*a(n-5) +a(n-6)
n=2: [order 31]
n=3: [order 21]
EXAMPLE
Some solutions for n=3 k=4
..0..0..0..2..2....0..1..2..2..2....2..2..1..1..0....1..1..0..1..1
..2..2..2..1..1....2..2..1..1..1....0..0..0..2..2....0..2..2..2..0
..2..2..2..0..0....2..2..2..2..2....0..0..1..2..2....0..0..0..0..0
..0..0..0..1..1....1..1..0..0..0....2..2..2..0..0....2..2..2..1..1
Table starts
....6......26.........98...........378.............1512................6018
...12......82........514..........3358............22396..............148820
...36.....676.......9604........142884..........2286144............36216324
...96....4338.....130890.......4140964........141857204..........4845741276
..264...29380....1876940.....127574544.......9704723126........733415243746
..720..196698...26726740....3901908720.....652274371446.....108383467365104
.1968.1321986..381984614..119751372066...44086966064930...16126266923705212
.5376.8867938.5442841504.3664449484670.2970697967221324.2391741572658733884
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Mar 11 2014
STATUS
approved