cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A264490 T(n,k)=Number of (n+1)X(k+1) arrays of permutations of 0..(n+1)*(k+1)-1 with each element having directed index change 2,-1 1,0 2,1 0,-1 -2,-2 or -1,0.

Original entry on oeis.org

1, 1, 3, 1, 1, 4, 1, 10, 12, 12, 1, 8, 36, 16, 25, 1, 35, 108, 212, 214, 52, 1, 42, 324, 788, 2144, 324, 121, 1, 130, 972, 4772, 21466, 9714, 2960, 261, 1, 194, 2916, 23076, 217049, 142352, 92052, 6442, 576, 1, 501, 8748, 122628, 2186741, 2517024, 2870927, 581575
Offset: 1

Views

Author

R. H. Hardin, Nov 14 2015

Keywords

Comments

Table starts
....1......1........1..........1...........1...........1...........1
....3......1.......10..........8..........35..........42.........130
....4.....12.......36........108.........324.........972........2916
...12.....16......212........788........4772.......23076......122628
...25....214.....2144......21466......217049.....2186741....22085009
...52....324.....9714.....142352.....2517024....42169152...714303376
..121...2960....92052....2870927....89130069..2775259622.86190450233
..261...6442...581575...30309632..1749889912.98973991195
..576..42656..4510937..463508815.47485981944
.1280.113575.31398740.5517128232

Examples

			Some solutions for n=4 k=4
..5..6..7..8..9....5..6..7..4..9....5..6..7..8..9....5..2..7..8..9
..0.11..2.13.14...10.11.12.13.14...10.11..2.13..4....0.11.12..3..4
.22.16..1..4..3...22..0..1..2..3...22..0..1.14..3...22.16..1.18.19
.20.21.18.23.24...20.21..8.23.24...20.21.18.23.24...20.21..6.23.14
.15.10.17.12.19...15.16.17.18.19...15.16.17.12.19...15.10.17.24.13
		

Crossrefs

Row 3 is A003946.

Formula

Empirical for column k:
k=1: a(n) = 2*a(n-1) +a(n-3) -2*a(n-4) +4*a(n-5) +a(n-6) -a(n-9)
k=2: [order 36]
Empirical for row n:
n=1: a(n) = a(n-1)
n=2: a(n) = 3*a(n-2) +2*a(n-3) +a(n-4) -a(n-5)
n=3: a(n) = 3*a(n-1)
n=4: a(n) = a(n-1) +16*a(n-2) +24*a(n-3) +16*a(n-4) +32*a(n-5) +32*a(n-6)
n=5: [order 39]
n=6: [order 10] for n>11