A264508 Number of (2+1)X(n+1) arrays of permutations of 0..n*3+2 with each element having directed index change -1,1 0,-1 0,1 or 1,0.

2, 2, 14, 38, 137, 432, 1417, 4554, 14710, 47394, 152762, 492284, 1586369, 5112128, 16473473, 53085636, 171065674, 551254626, 1776394534, 5724372546, 18446568521, 59443412528, 191554172489, 617276369198, 1989150291038, 6409964077506

Offset

1,1

Comments

Row 2 of A264506.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 2*a(n-1) +7*a(n-2) -8*a(n-3) -9*a(n-4) +10*a(n-5) -a(n-6) +a(n-8) -10*a(n-9) +9*a(n-10) +8*a(n-11) -7*a(n-12) -2*a(n-13) +a(n-14)

Example

Some solutions for n=4
..1..0..3..4..8....1..2..3..7..8....1..2..6..4..3....1..2..6..4..3
..6.10..2..7.13....0.10.11.12..4....0..7.11.12..8....0..7..8.12.13
..5.12.11.14..9....5..6.13.14..9....5.10.13.14..9....5.10.11.14..9

Crossrefs

Cf. A264506.

Sequence in context: A151437 A235349 A226157 * A194689 A277556 A321179

Adjacent sequences: A264505 A264506 A264507 * A264509 A264510 A264511

Keyword

nonn

Author

R. H. Hardin, Nov 15 2015

Status

approved