A223673 Number of 6Xn 0..1 arrays with rows, diagonals and antidiagonals unimodal.

64, 4096, 61996, 321163, 1023339, 2715255, 6789502, 16634224, 40086061, 94218637, 214377471, 470774847, 998649425, 2051656863, 4092563126, 7942987666, 15025087905, 27743027247, 50072239147, 88451496245, 153108327757

Offset: 1

Author

R. H. Hardin Mar 25 2013

Keywords

• nonn

Comments

Row 6 of A223669

Examples

			Some solutions for n=4
..0..0..1..0....0..0..0..0....0..0..0..1....0..0..0..1....0..0..0..0
..0..1..0..0....0..0..0..0....0..1..1..0....0..1..1..0....0..0..0..0
..0..0..1..0....1..0..0..0....1..1..1..1....0..1..1..0....0..1..0..0
..0..0..0..1....0..0..0..0....1..1..1..1....1..1..0..0....1..0..0..0
..0..1..1..1....0..1..0..0....1..1..1..0....0..0..0..0....0..1..0..0
..0..1..1..1....0..0..0..0....1..1..1..0....0..0..0..0....0..0..0..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..129

Formula

Empirical: a(n) = (271/5443200)*n^12 - (5527/1995840)*n^11 + (284203/2721600)*n^10 - (97799/51840)*n^9 - (4335667/259200)*n^8 + (68712079/30240)*n^7 - (50002254419/680400)*n^6 + (495395854627/362880)*n^5 - (42767475646507/2721600)*n^4 + (1367715597167/12960)*n^3 - (3261545344751/10800)*n^2 - (3687840940699/6930)*n + 4224261488 for n>20