A250687 Number of (n+1)X(4+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.
11150, 60508, 324648, 1670016, 8038566, 36673634, 160222342, 676640344, 2784280670, 11235235268, 44688274606, 175922640288, 687672281246, 2676084468860, 10388862354030, 40297745223480, 156374569711646
Offset: 1
Keywords
Examples
Some solutions for n=2 ..3..2..1..0..0....0..3..2..0..0....1..2..0..2..2....3..2..1..0..0 ..3..2..1..1..1....0..3..2..0..2....1..3..1..3..3....3..3..2..1..1 ..3..3..3..3..3....0..3..2..0..2....1..3..1..3..3....3..3..3..2..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 27*a(n-1) -331*a(n-2) +2439*a(n-3) -12049*a(n-4) +42129*a(n-5) -107225*a(n-6) +201069*a(n-7) -277706*a(n-8) +278928*a(n-9) -197984*a(n-10) +94032*a(n-11) -26784*a(n-12) +3456*a(n-13) for n>17
Comments