A224005 Number of 7Xn 0..2 arrays with antidiagonals unimodal and rows and diagonals nondecreasing.
2187, 102069, 739672, 2743444, 7400832, 16795265, 34534687, 67029572, 125640165, 230434296, 416688642, 746070578, 1325631005, 2339607173, 4101879980, 7141164265, 12337189420, 21134985710, 35876879602, 60309132371, 100343859256
Offset: 1
Keywords
Examples
Some solutions for n=3 ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0 ..1..1..1....0..0..1....0..0..1....0..1..1....0..1..1....1..2..2....1..2..2 ..0..1..2....0..0..1....0..1..1....1..2..2....0..1..2....0..2..2....0..1..2 ..0..2..2....0..1..1....0..1..2....0..1..2....0..1..1....1..1..2....0..1..1 ..0..0..2....1..1..2....1..1..2....1..1..1....0..0..2....0..1..1....0..0..2 ..0..1..2....0..1..2....0..1..2....0..1..2....0..0..2....0..2..2....0..0..2 ..0..0..2....0..1..1....0..1..1....0..2..2....0..2..2....2..2..2....0..2..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = (1/203212800)*n^14 + (1/29030400)*n^13 + (817/319334400)*n^12 + (2627/63866880)*n^11 + (8279/9676800)*n^10 + (408523/29030400)*n^9 + (46918247/203212800)*n^8 + (17877667/5806080)*n^7 + (73580257/1814400)*n^6 + (1465470497/3628800)*n^5 + (385797089/100800)*n^4 + (7741678111/362880)*n^3 + (387997970341/3880800)*n^2 - (400735465/1386)*n - 1233287 for n>10
Comments