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.

A264520 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 -1,0 0,2 -1,-2 or 1,0.

Original entry on oeis.org

1, 1, 0, 1, 0, 1, 2, 1, 3, 0, 4, 2, 9, 0, 1, 6, 4, 42, 36, 12, 0, 9, 8, 196, 228, 144, 0, 1, 12, 16, 644, 1444, 1644, 576, 46, 0, 16, 32, 2116, 8018, 18769, 10368, 2116, 0, 1, 24, 64, 6854, 44521, 169195, 186624, 65182, 8281, 177, 0, 36, 128, 22201, 258264, 1525225
Offset: 1

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Author

R. H. Hardin, Nov 16 2015

Keywords

Comments

Table starts
.1...1......1........2..........4............6..............9...............12
.0...0......1........2..........4............8.............16...............32
.1...3......9.......42........196..........644...........2116.............6854
.0...0.....36......228.......1444.........8018..........44521...........258264
.1..12....144.....1644......18769.......169195........1525225.........14158040
.0...0....576....10368.....186624......2856816.......43731769........696507612
.1..46...2116....65182....2007889.....50099452.....1250046736......33040712340
.0...0...8281...414414...20738916....868998834....36412654041....1611878726112
.1.177..31329..2603670..216384100..14882827790..1023636039001...75733369600339
.0...0.121801.16540506.2246191236.256959272592.29395568245824.3617985452054688

Examples

			Some solutions for n=4 k=4
..7..8..9..1..2....7..8..0..1..2....7..8..0..1..2....5..8..7..1..2
..0.13.14..3..4...10.11.14..3..4...10.11.12..3..4....0.13.14..3..4
..5..6.10.18.12....5..6.17.18..9....5..6.19.18..9...17..6.10.11..9
.20.11.22.23.24...22.23.12.13.24...20.23.24.13.14...22.21.12.23.24
.15.16.17.21.19...15.16.20.21.19...15.16.17.21.22...15.16.20.18.19
		

Crossrefs

Row 1 is A224809(n+1).
Row 2 is A000079(n-3).

Formula

Empirical for column k:
k=1: a(n) = a(n-2)
k=2: a(n) = 6*a(n-2) -11*a(n-4) +13*a(n-6) -11*a(n-8) +6*a(n-10) -a(n-12)
k=3: [order 19]
k=4: [order 84]
k=5: [order 90]
Empirical for row n:
n=1: a(n) = a(n-1) +a(n-3) -a(n-4) +a(n-5) +a(n-6) -a(n-9)
n=2: a(n) = 2*a(n-1)