cp's OEIS Frontend

A202070 Number of arrays of n+2 integers in -2..2 with sum zero and the sum of every adjacent pair being odd.

%I A202070 #7 Jul 22 2025 16:27:56
%S A202070 4,20,26,0,96,524,726,0,2760,15560,22084,0,85120,487564,700966,0,
%T A202070 2723256,15746520,22820940,0,89115840,518517560,755594620,0,
%U A202070 2961237136,17306539536,25319793096,0,99494853120,583417062540,856125569286,0
%N A202070 Number of arrays of n+2 integers in -2..2 with sum zero and the sum of every adjacent pair being odd.
%C A202070 Column 2 of A202076
%H A202070 R. H. Hardin, <a href="/A202070/b202070.txt">Table of n, a(n) for n = 1..210</a>
%e A202070 Some solutions for n=10
%e A202070 .-1....0....1....2....1...-2....1...-2...-2....2...-1...-2...-2...-1....1....1
%e A202070 ..0...-1....0...-1....0....1....0....1...-1...-1....0....1....1...-2....2....2
%e A202070 ..1....2...-1...-2...-1....0...-1...-2...-2....0...-1....0....0...-1....1...-1
%e A202070 ..0....1....2...-1...-2....1....0...-1....1....1....2....1...-1....0....2...-2
%e A202070 .-1...-2....1....2...-1...-2....1...-2....2...-2...-1....2....0...-1...-1...-1
%e A202070 ..0....1....0...-1....0....1...-2....1...-1....1....2...-1....1....2....0....2
%e A202070 ..1....2...-1....2...-1....0...-1...-2....0....0....1...-2....2....1...-1....1
%e A202070 .-2...-1....0...-1....2....1....2....1...-1...-1...-2...-1....1...-2....2....0
%e A202070 ..1....0...-1....2...-1....0...-1....2....0....2...-1...-2....0....1...-1....1
%e A202070 ..0...-1...-2....1....2...-1...-2....1....1...-1....2....1...-1....2...-2....0
%e A202070 .-1...-2....1...-2...-1....0....1....2....2....0....1....2....0...-1...-1...-1
%e A202070 ..2....1....0...-1....2....1....2....1....1...-1...-2....1...-1....2...-2...-2
%K A202070 nonn
%O A202070 1,1
%A A202070 _R. H. Hardin_ Dec 10 2011