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.

A264878 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 0,1 0,-1 -2,0 or 1,1.

Original entry on oeis.org

1, 0, 1, 1, 0, 1, 0, 1, 0, 2, 1, 1, 5, 0, 3, 0, 7, 4, 20, 0, 4, 1, 20, 65, 12, 56, 0, 5, 0, 49, 228, 572, 36, 137, 0, 6, 1, 175, 1101, 2348, 3613, 108, 295, 0, 8, 0, 323, 4832, 22152, 22400, 19372, 324, 709, 0, 11, 1, 1085, 18501, 129230, 356692, 207424, 103585, 972, 1983, 0
Offset: 1

Views

Author

R. H. Hardin, Nov 27 2015

Keywords

Comments

Table starts
..1.0....1....0........1..........0............1..............0
..1.0....1....1........7.........20...........49............175
..1.0....5....4.......65........228.........1101...........4832
..2.0...20...12......572.......2348........22152.........129230
..3.0...56...36.....3613......22400.......356692........3303808
..4.0..137..108....19372.....207424......4747695.......78535556
..5.0..295..324...103585....1946752.....68488297.....1924357508
..6.0..709..972...629654...18265856...1050281271....47123513432
..8.0.1983.2916..3930725..171168256..16268725036..1152731721920
.11.0.5280.8748.23940621.1602206720.247512489984.28078658475952

Examples

			Some solutions for n=4 k=4
..1..2..3..4.14...10..2.12..4.14....1..2.12..4.14...10..2..3..4.14
.15..0..8..9.19....6..0..1..9..3...15..0..8..9..3....6..0..1..9.19
.20..5..6..7.24...20..5.22..7..8...20..5..6..7.24...20..5.22..7..8
.16.10.11.12.13...16.17.11.19.13...16.10.11.19.13...16.17.11.12.13
.21.22.23.17.18...21.15.23.24.18...21.22.23.17.18...21.15.23.24.18
		

Crossrefs

Column 1 is A003520(n+1).
Column 4 is A003946(n-2).

Formula

Empirical for column k:
k=1: a(n) = a(n-1) +a(n-5)
k=2: a(n) = a(n-1)
k=3: [order 45]
k=4: a(n) = 3*a(n-1) for n>3
Empirical for row n:
n=1: a(n) = a(n-2)
n=2: [order 20]
n=3: [order 46]