A252936 Number of nX6 nonnegative integer arrays with upper left 0 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.
26, 176, 1343, 10920, 86488, 578342, 2952734, 11219797, 32649081, 76641323, 153453179, 273544411, 447399739, 685504923, 998345723, 1396407899, 1890177211, 2490139419, 3206780283, 4050585563, 5032041019, 6161632411, 7449845499
Offset: 1
Keywords
Examples
Some solutions for n=4 ..0..0..0..1..1..2....0..1..2..2..2..2....0..1..2..2..2..2....0..1..1..1..1..2 ..0..0..0..1..2..2....0..1..2..2..3..3....1..1..2..3..3..3....0..1..1..1..2..2 ..0..1..1..1..2..2....1..1..2..2..3..4....1..2..2..3..3..3....0..1..1..1..2..3 ..1..1..1..1..2..2....2..2..2..3..3..4....2..2..3..3..3..3....0..1..2..2..2..3
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = (5242880/3)*n^3 - 36032512*n^2 + (765093664/3)*n - 618047397 for n>10
Comments