A264874 Number of (n+1)X(3+1) arrays of permutations of 0..n*4+3 with each element having directed index change 0,1 0,-1 -2,0 or 1,1.

1, 1, 5, 20, 56, 137, 295, 709, 1983, 5280, 13521, 34173, 85993, 219721, 567894, 1461417, 3737198, 9546206, 24410323, 62518425, 160259301, 410562684, 1050999521, 2690293140, 6888161028, 17639430568, 45173289641, 115675667529

Offset

1,3

Comments

Column 3 of A264878.

Links

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

Formula

Empirical: a(n) = a(n-1) +5*a(n-3) +4*a(n-4) +21*a(n-5) +21*a(n-6) +13*a(n-7) -58*a(n-8) -70*a(n-9) -157*a(n-10) -198*a(n-11) -102*a(n-12) +209*a(n-13) +273*a(n-14) +553*a(n-15) +594*a(n-16) +289*a(n-17) -359*a(n-18) -430*a(n-19) -917*a(n-20) -765*a(n-21) -338*a(n-22) +401*a(n-23) +387*a(n-24) +812*a(n-25) +551*a(n-26) +167*a(n-27) -301*a(n-28) -174*a(n-29) -444*a(n-30) -208*a(n-31) -21*a(n-32) +107*a(n-33) +37*a(n-34) +134*a(n-35) +34*a(n-36) -17*a(n-38) -3*a(n-39) -19*a(n-40) -2*a(n-41) +a(n-43) +a(n-45)

Example

Some solutions for n=4
..1..2..3.11....1..0..3.11....1..2..3.11....1..2..3.11....1..0..3..2
.12..0..7.15....5..4..7..2...12..0..7..6....5..0..7.15....5..4..7.15
.16..4..5..6...16..8..9..6....9..4..5.10...16..4.18..6...16..8.11..6
.13..8..9.10...13.12.15.10...13..8.15.14...13..8..9.10...13.12..9.10
.17.18.19.14...17.18.19.14...17.16.19.18...17.12.19.14...17.18.19.14

Crossrefs

Cf. A264878.

Sequence in context: A062988 A181936 A226639 * A270092 A272277 A272507

Adjacent sequences: A264871 A264872 A264873 * A264875 A264876 A264877

Keyword

nonn

Author

R. H. Hardin, Nov 27 2015

Status

approved