login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A263513
Number of (n+1)X(2+1) arrays of permutations of 0..n*3+2 filled by rows with each element moved a city block distance of 0 or 1, and rows and columns in increasing lexicographic order.
1
7, 35, 208, 1198, 7022, 41035, 240237, 1406038, 8230727, 48180019, 282036139, 1650978414, 9664491503, 56573952014, 331172398977, 1938615771254, 11348262181134, 66430417127424, 388870142636120, 2276366675982209
OFFSET
1,1
COMMENTS
Column 2 of A263519.
LINKS
FORMULA
Empirical: a(n) = 7*a(n-1) -a(n-2) -39*a(n-3) +24*a(n-4) +57*a(n-5) -33*a(n-6) -28*a(n-7) +13*a(n-8) +3*a(n-9) -a(n-10)
EXAMPLE
Some solutions for n=4
..0..1..5....0..1..2....0..1..2....0..2..5....0..2..5....0..1..2....0..1..2
..4..3..2....3..4..8....3..4..8....3..1..4....3..1..8....3..4..5....4..3..5
..7..6..8....9..6..5....6..7..5....7..6.11....6..4..7....7..6..8....9..6..7
..9.11.10...10..7.11....9.10.14....9.13..8....9.10.14...10..9.11...10.13..8
.12.14.13...13.12.14...12.13.11...12.10.14...13.12.11...12.14.13...12.14.11
CROSSREFS
Cf. A263519.
Sequence in context: A360083 A267712 A377158 * A274073 A177261 A105926
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 19 2015
STATUS
approved