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.

A223789 T(n,k)=Number of nXk 0..2 arrays with rows, diagonals and antidiagonals unimodal.

Original entry on oeis.org

3, 9, 9, 22, 81, 27, 46, 484, 729, 81, 86, 2116, 8635, 6561, 243, 148, 7396, 62365, 151580, 59049, 729, 239, 21904, 334230, 1560013, 2703137, 531441, 2187, 367, 57121, 1455816, 11012718, 39387861, 48302789, 4782969, 6561, 541, 134689, 5425943
Offset: 1

Views

Author

R. H. Hardin Mar 27 2013

Keywords

Comments

Table starts
.....3..........9............22..............46................86
.....9.........81...........484............2116..............7396
....27........729..........8635...........62365............334230
....81.......6561........151580.........1560013..........11012718
...243......59049.......2703137........39387861.........343454446
...729.....531441......48302789......1026135371.......11150023974
..2187....4782969.....862007289.....27088106846......377163884938
..6561...43046721...15379566078....715394830136....12972494260444
.19683..387420489..274427327200..18858304684055...446829906314726
.59049.3486784401.4896915028511.496722962933967.15355124632228358

Examples

			Some solutions for n=3 k=4
..2..2..2..1....1..2..0..0....1..1..2..2....1..2..1..1....0..0..0..0
..0..2..2..1....0..0..1..0....0..2..2..1....1..1..2..0....0..1..2..0
..2..1..0..0....0..1..0..0....0..2..0..0....2..2..2..2....0..0..1..0
		

Crossrefs

Column 1 is A000244
Column 2 is A001019
Row 1 is A223718
Row 2 is A223719

Formula

Empirical for column k:
k=1: a(n) = 3*a(n-1)
k=2: a(n) = 9*a(n-1)
k=3: [order 15]
k=4: [order 80]
Empirical: rows n=1..5 are polynomials of order 4*n for k>0,0,1,8,15