A223740 Number of nX6 0..2 arrays with rows, columns, diagonals and antidiagonals unimodal.
148, 21904, 1082738, 24527068, 340038574, 3437215802, 28017383049, 195114520747, 1200776938428, 6667000031694, 33855136108849, 158770607250059, 692749181797191, 2828862453161793, 10864955922680147, 39417487036715031
Offset: 1
Keywords
Examples
Some solutions for n=3 ..0..0..0..1..1..2....0..0..0..2..1..0....0..0..1..1..0..0....0..0..0..0..0..0 ..0..0..0..1..2..2....0..0..1..2..1..1....0..0..1..1..2..0....0..0..2..2..2..2 ..0..0..1..1..1..1....0..0..1..1..1..0....0..0..0..1..2..2....2..2..1..1..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..44
Formula
Empirical: a(n) = (114400861/793412278431252480000)*n^24 - (51075794587/8617338912961658880000)*n^23 + (1980369833107/6744004366665646080000)*n^22 - (10175245261/1277273554292736000)*n^21 + (1636653578471/10304055564042240000)*n^20 + (1969068275129/14597412049059840000)*n^19 - (992154752050453/8066990869217280000)*n^18 + (146561615547371/29877743960064000)*n^17 - (419840704716587677/3796230997278720000)*n^16 + (43611886853741881/28759325736960000)*n^15 - (426135162517318237/60872508702720000)*n^14 - (1461996088631538851/6214068596736000)*n^13 + (341585746531181711516743/41758540970065920000)*n^12 - (18495577502515890115483/105450861035520000)*n^11 + (3017647739520402646603697/949057749319680000)*n^10 - (787602150530565904976843/15817629155328000)*n^9 + (21676051131880174432691909/33894919618560000)*n^8 - (307946068460663534824170109/48017802792960000)*n^7 + (103203788635493619721225240009/2128789257154560000)*n^6 - (864678379682656262490199981/3225438268416000)*n^5 + (10065213443478593696277188029/9565638001920000)*n^4 - (7780601713723052220368499439/2710264100544000)*n^3 + (755525652858782115616121/134437703400)*n^2 - (7954542427408468560391/892371480)*n + 10219818700267 for n>18
Comments