cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A252935 Number of n X 5 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.

Original entry on oeis.org

15, 83, 494, 3067, 17962, 86488, 320270, 917811, 2127013, 4211511, 7437417, 12070971, 18378413, 26625983, 37079921, 50006467, 65671861, 84342343, 106284153, 131763531, 161046717, 194399951, 232089473, 274381523, 321542341
Offset: 1

Views

Author

R. H. Hardin, Dec 24 2014

Keywords

Examples

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

Crossrefs

Column 5 of A252938.

Formula

Empirical: a(n) = (133120/3)*n^3 - 760496*n^2 + (13526246/3)*n - 9199709 for n>8.
Conjectures from Colin Barker, Dec 07 2018: (Start)
G.f.: x*(15 + 23*x + 252*x^2 + 1529*x^3 + 8341*x^4 + 31149*x^5 + 70316*x^6 + 86878*x^7 + 49399*x^8 + 15733*x^9 + 2477*x^10 + 128*x^11) / (1 - x)^4.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>12.
(End)