A223975 T(n,k)=Number of nXk 0..2 arrays with rows and antidiagonals unimodal.

3, 9, 9, 22, 81, 27, 46, 484, 729, 81, 86, 2116, 9515, 6561, 243, 148, 7396, 76092, 186004, 59049, 729, 239, 21904, 440628, 2558848, 3628696, 531441, 2187, 367, 57121, 2026448, 22935921, 84988435, 70779056, 4782969, 6561, 541, 134689, 7829639

Offset: 1

Author

R. H. Hardin Mar 30 2013

Keywords

• nonn
• tabl

Comments

Table starts

.....3..........9.............22...............46.................86

.....9.........81............484.............2116...............7396

....27........729...........9515............76092.............440628

....81.......6561.........186004..........2558848...........22935921

...243......59049........3628696.........84988435.........1140963027

...729.....531441.......70779056.......2809740785........55803232969

..2187....4782969.....1380511272......92756321858......2708281019793

..6561...43046721....26926081924....3060966419662....131014406127439

.19683..387420489...525177301935..100999995564503...6329626912147424

.59049.3486784401.10243271456697.3332485315028073.305632588672082728

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..286

Crossrefs

Column 1 is A000244

Column 2 is A001019

Row 1 is A223718

Row 2 is A223719

Formula

Empirical: columns k=1..6 have recurrences of order 1,1,7,18,43,91

Empirical: rows n=1..7 are polynomials of degree 4*n for k>0,0,0,0,2,3,4