A267234 Number of length-5 0..n arrays with no following elements greater than or equal to the first repeated value.

7, 103, 564, 1980, 5375, 12327, 25088, 46704, 81135, 133375, 209572, 317148, 464919, 663215, 924000, 1260992, 1689783, 2227959, 2895220, 3713500, 4707087, 5902743, 7329824, 9020400, 11009375, 13334607, 16037028, 19160764, 22753255, 26865375

Offset: 1

Author

R. H. Hardin, Jan 12 2016

Keywords

• nonn

Examples

			Some solutions for n=6:
..3....6....4....4....0....0....4....6....5....5....5....0....2....0....4....0
..2....6....2....1....4....5....1....0....4....0....1....3....5....1....1....2
..1....2....3....6....3....1....6....3....0....1....4....6....6....6....0....1
..6....1....6....6....6....3....3....4....4....0....5....3....4....5....1....3
..0....4....6....5....5....1....4....6....5....5....6....5....4....4....1....4
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Row 5 of A267232.

Formula

Empirical: a(n) = n^5 + (37/12)*n^4 + (5/2)*n^3 + (5/12)*n^2.

Conjectures from Colin Barker, Jan 10 2019: (Start)

G.f.: x*(7 + 61*x + 51*x^2 + x^3) / (1 - x)^6.

a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.

(End)