cp's OEIS Frontend

A202128 Number of -n..n arrays of 7 elements with first, second and third differences also in -n..n.

%I A202128 #7 Jul 22 2025 16:29:42
%S A202128 47,1517,15101,85771,345241,1104357,2993875,7169025,15586785,31358615,
%T A202128 59213403,106061265,181644529,299379215,477297063,739082975,
%U A202128 1115418273,1645395261,2378011923,3374165639,4708618657,6472020879,8773706563
%N A202128 Number of -n..n arrays of 7 elements with first, second and third differences also in -n..n.
%C A202128 Row 7 of A202124
%H A202128 R. H. Hardin, <a href="/A202128/b202128.txt">Table of n, a(n) for n = 1..172</a>
%e A202128 Some solutions for n=5
%e A202128 .-3...-2...-2...-2...-4...-4...-4...-2...-2...-2...-4...-1...-2...-1...-1...-2
%e A202128 .-4...-5...-1...-3...-4...-2...-4...-5...-4...-3...-4...-2...-1...-3...-2...-1
%e A202128 .-2...-5....1...-3...-5...-2...-4...-5...-1...-4...-5...-5....0...-1...-3....2
%e A202128 .-1...-3....0...-3...-5...-1...-4...-3....3...-5...-2...-5....0....0...-3....4
%e A202128 .-3....1...-1...-1...-3....0...-4...-2....5...-4....1...-5....2....1...-4....5
%e A202128 .-3....2...-1...-2....0...-3...-4...-1....5...-1....1...-2....5...-1...-3....2
%e A202128 .-3....0....2...-2...-1...-5...-1....2....4....1....3....1....5...-3....0...-2
%K A202128 nonn
%O A202128 1,1
%A A202128 _R. H. Hardin_ Dec 11 2011