A264417 Number of (n+1)X(2+1) arrays of permutations of 0..n*3+2 with each element having directed index change 0,1 2,2 1,0 -1,2 -2,-1 or -1,-1.

2, 3, 20, 85, 351, 1462, 6021, 25188, 104870, 437164, 1821829, 7592125, 31637827, 131836355, 549380672, 2289347792, 9540065618, 39754914509, 165664757540, 690350003398, 2876792156808, 11988025615109, 49955906989734

Offset

1,1

Comments

Column 2 of A264422.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +a(n-2) +7*a(n-3) +29*a(n-4) +13*a(n-5) +64*a(n-6) +161*a(n-7) -12*a(n-8) +82*a(n-9) -257*a(n-10) -1288*a(n-11) -1368*a(n-12) -2536*a(n-13) -3049*a(n-14) -516*a(n-15) -4280*a(n-16) -1979*a(n-17) +1117*a(n-18) +1724*a(n-19) +10832*a(n-20) +12414*a(n-21) -146*a(n-22) +13134*a(n-23) +10828*a(n-24) -6040*a(n-25) +4027*a(n-26) -4916*a(n-27) -23812*a(n-28) -5121*a(n-29) +3663*a(n-30) -6131*a(n-31) -1747*a(n-32) -1254*a(n-33) +1643*a(n-34) -722*a(n-35) -905*a(n-36) +386*a(n-37) +72*a(n-38) -695*a(n-39) -249*a(n-40) +334*a(n-41) +108*a(n-42) -44*a(n-43) +64*a(n-44) +149*a(n-45) -10*a(n-46) +36*a(n-47) +29*a(n-48) +46*a(n-49) -2*a(n-50) -8*a(n-51) +4*a(n-52) +5*a(n-53) +2*a(n-54) +a(n-55) +a(n-56)

Example

Some solutions for n=4
..4..5..1....4..5..1....4..5..3....4..5..3....4..5..1....4..5..1....4..8..1
..0..8..2....0..8..2...10..1..2....0..1..2....7..8..2....0..8..2....0.11..2
..3..6..7....3.11..7...13.14..0...10.11..7...10.11..0...10..6..7...10.14..5
.13.14.12....6.14.12....6..7..8...13.14..8....6.14..3...13.14..3....6..7..3
..9.10.11....9.10.13....9.12.11....9.12..6....9.12.13....9.12.11....9.12.13

Crossrefs

Cf. A264422.

Sequence in context: A338084 A087301 A292122 * A348311 A066166 A007113

Adjacent sequences: A264414 A264415 A264416 * A264418 A264419 A264420

Keyword

nonn

Author

R. H. Hardin, Nov 12 2015

Status

approved