cp's OEIS Frontend

A202126 Number of -n..n arrays of 5 elements with first, second and third differences also in -n..n.

%I A202126 #10 Jul 22 2025 16:29:28
%S A202126 27,293,1509,5205,14063,32267,65773,122709,213697,352075,554381,
%T A202126 840659,1234569,1764039,2461495,3363883,4513485,5958085,7750859,
%U A202126 9951423,12625883,15846605,19693499,24253977,29622535,35902357,43205125,51650425
%N A202126 Number of -n..n arrays of 5 elements with first, second and third differences also in -n..n.
%C A202126 Row 5 of A202124
%H A202126 R. H. Hardin, <a href="/A202126/b202126.txt">Table of n, a(n) for n = 1..195</a>
%F A202126 Empirical: a(n) = a(n-1) +3*a(n-3) -2*a(n-4) -4*a(n-6) +3*a(n-9) +3*a(n-10) -4*a(n-13) -2*a(n-15) +3*a(n-16) +a(n-18) -a(n-19).
%F A202126 a(n) ~ (44471/16200)*n^5. - _Robert Israel_, Jun 28 2019
%e A202126 Some solutions for n=5
%e A202126 .-2....3...-3...-2....4....5...-1...-1....3....3...-3....3...-5...-2....1....4
%e A202126 .-4....1....1...-2....5....1....0...-4....4....2...-5...-1...-4....0....0....5
%e A202126 .-5...-1....1...-2....3....0....1...-3....3....2...-3...-1...-4....2....1....5
%e A202126 .-5....1....1...-1....2....2....2...-3....1....2....1....2...-3....2...-1....4
%e A202126 .-2....4...-2....1....5....5....3...-4...-3...-3....3....5....2....4...-3...-1
%K A202126 nonn
%O A202126 1,1
%A A202126 _R. H. Hardin_ Dec 11 2011