login
A223684
Number of 6Xn 0..1 arrays with rows and antidiagonals unimodal
1
64, 4096, 83737, 744272, 4106403, 17068664, 58944337, 178002044, 484800960, 1215412314, 2845433373, 6286999243, 13216899344, 26605753969, 51547601046, 96528061541, 175319673499, 309757515173, 533729732564, 898819275234
OFFSET
1,1
COMMENTS
Row 6 of A223680
LINKS
FORMULA
Empirical: a(n) = (271/5443200)*n^12 + (2327/3326400)*n^11 + (44081/1360800)*n^10 + (67031/362880)*n^9 + (1007557/226800)*n^8 + (1582/675)*n^7 + (211210703/1360800)*n^6 - (60265871/120960)*n^5 + (11265884461/5443200)*n^4 - (118533836/14175)*n^3 + (2826245099/151200)*n^2 - (113088191/3960)*n + 23503 for n>3
EXAMPLE
Some solutions for n=3
..1..1..0....1..0..0....0..0..1....1..0..0....1..1..0....0..0..1....1..1..1
..0..1..1....0..1..0....1..0..0....1..1..1....0..0..1....0..1..0....0..1..1
..1..1..0....0..1..1....0..1..1....1..1..1....0..1..0....1..1..1....1..1..1
..0..0..1....1..1..0....1..0..0....0..0..0....0..0..1....0..1..1....0..1..1
..0..1..1....1..1..0....0..1..1....0..1..0....0..1..0....0..0..0....0..1..1
..0..1..1....1..1..0....1..0..0....1..1..0....0..0..0....0..1..0....0..0..0
CROSSREFS
Sequence in context: A189693 A188744 A188996 * A189068 A189193 A188878
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 25 2013
STATUS
approved