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

1,1

Comments

Row 6 of A223669

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

Example

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

Crossrefs

Sequence in context: A017571 A016746 A189268 * A189621 A189693 A188744

Adjacent sequences: A223670 A223671 A223672 * A223674 A223675 A223676

Keyword

nonn

Author

R. H. Hardin Mar 25 2013

Status

approved