cp's OEIS Frontend

A250272 Number of length n+1 0..3 arrays with the sum of the squares of adjacent differences multiplied by some arrangement of +-1 equal to zero.

%I A250272 #6 Jul 23 2025 12:15:59
%S A250272 4,20,52,240,984,4412,20252,91808,406748,1759740,7455484,31056840,
%T A250272 127719296,520368940,2106440916,8489650480,34118389900,136865613068,
%U A250272 548408972596,2195889958776,8788865312160,35167823753468,140699850287804
%N A250272 Number of length n+1 0..3 arrays with the sum of the squares of adjacent differences multiplied by some arrangement of +-1 equal to zero.
%C A250272 Column 3 of A250277
%H A250272 R. H. Hardin, <a href="/A250272/b250272.txt">Table of n, a(n) for n = 1..55</a>
%F A250272 Empirical: a(n) = 22*a(n-1) -221*a(n-2) +1348*a(n-3) -5594*a(n-4) +16756*a(n-5) -37474*a(n-6) +63792*a(n-7) -83421*a(n-8) +83878*a(n-9) -64369*a(n-10) +37052*a(n-11) -15496*a(n-12) +4448*a(n-13) -784*a(n-14) +64*a(n-15) for n>18
%e A250272 Some solutions for n=6
%e A250272 ..2....1....2....0....1....0....1....3....0....1....3....3....3....3....0....0
%e A250272 ..3....3....0....2....0....1....3....2....2....1....3....0....0....1....3....2
%e A250272 ..1....3....1....3....2....0....2....3....3....3....3....1....3....0....2....0
%e A250272 ..0....3....3....2....3....1....0....0....2....3....1....0....1....0....1....1
%e A250272 ..0....2....1....3....2....0....1....3....2....0....2....0....3....0....0....0
%e A250272 ..2....3....3....2....2....2....0....2....2....1....3....3....1....3....3....0
%e A250272 ..2....1....0....2....1....2....3....3....0....3....1....3....3....1....2....0
%K A250272 nonn
%O A250272 1,1
%A A250272 _R. H. Hardin_, Nov 16 2014