A253003 Number of nX7 nonnegative integer arrays with upper left 0 and lower right its king-move distance away minus 3 and every value within 3 of its king move distance from the upper left and every value increasing by 0 or 1 with every step right, diagonally se or down.
20, 140, 1028, 7235, 39758, 122833, 122833, 4915726, 59154789, 329035981, 1124010769, 2853903059, 5973571711, 10950733467, 18255251895, 28357151187, 41726455535, 58833189131, 80147376167, 106139040835, 137278207327
Offset: 1
Keywords
Examples
Some solutions for n=6 ..0..1..1..1..1..2..3....0..0..1..1..1..2..3....0..1..1..1..2..3..3 ..1..1..1..1..2..2..3....0..0..1..1..2..2..3....0..1..2..2..2..3..3 ..1..1..1..1..2..2..3....0..1..1..1..2..2..3....1..1..2..2..2..3..3 ..1..1..2..2..2..3..3....0..1..1..2..2..3..3....1..1..2..2..3..3..3 ..1..2..2..2..3..3..3....1..1..1..2..3..3..3....2..2..2..3..3..3..3 ..2..2..2..3..3..3..3....2..2..2..2..3..3..3....2..2..3..3..3..3..3
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = (235012096/3)*n^3 - 2126491008*n^2 + (58625640404/3)*n - 60801081325 for n>12
Comments