A228264 - OEIS

%I #8 Sep 01 2013 22:33:22

%S 255,6305,58911,315601,1161855,3298681,7795501,16171769,30424997,

%T 53235009,87985685,138831929,210793509,309786737,442759141,617796857,

%U 844148261,1132324321,1494179237,1942991081,2493542437,3162201041

%N Number of third differences of arrays of length 8 of numbers in 0..n.

%C Row 5 of A228260

%H R. H. Hardin, <a href="/A228264/b228264.txt">Table of n, a(n) for n = 1..30</a>

%F Empirical: a(n) = 672*n^5 - 1152*n^4 - 3340*n^3 + 8908*n^2 + 4108*n - 14279 for n>13

%e Some solutions for n=4

%e .-2..-12..-12...-4...-4...-6....6...-4...-4....4...-8...-6...-6..-10...-2...-6

%e .-6...12...10....9....6....2...-6....0...-3...-4...-2....4....5....5....7...14

%e ..8...-9...-6...-6...-3....1....6....4....4...-5....7....0...-5....6...-1..-12

%e .-4....0....3....4...-4....4...-6...-2....4....8...-4...-4....4..-13...-5....1

%e ..4....7....0...-9....9..-11...-3....4..-12...-3....5....5...-6...10....2....7

%K nonn

%O 1,1

%A _R. H. Hardin_ Aug 19 2013