cp's OEIS Frontend

A232317 Number of (1+1)X(n+1) 0..1 arrays with every element equal to some horizontal or antidiagonal neighbor, with top left element zero.

%I A232317 #12 Jul 23 2025 07:18:20
%S A232317 2,5,16,52,169,549,1784,5797,18837,61210,198899,646313,2100164,
%T A232317 6824385,22175521,72058322,234150159,760860029,2472379204,8033880997,
%U A232317 26105721877,84829326570,275648943179,895708394113,2910562681764,9457737786265
%N A232317 Number of (1+1)X(n+1) 0..1 arrays with every element equal to some horizontal or antidiagonal neighbor, with top left element zero.
%C A232317 Row 1 of A232316
%H A232317 R. H. Hardin, <a href="/A232317/b232317.txt">Table of n, a(n) for n = 1..210</a>
%F A232317 Empirical: a(n) = 3*a(n-1) +a(n-2) -2*a(n-4) for n>5.
%F A232317 Empirical: G.f.: 2*x -x^2*(-5-x+x^2+3*x^3) / ( 1-3*x-x^2+2*x^4 ). - _R. J. Mathar_, Nov 24 2013
%e A232317 Some.solutions.for.n=7
%e A232317 ..0..0..1..1..0..0..0..1....0..0..0..1..1..0..0..0....0..0..0..1..1..1..0..0
%e A232317 ..1..1..1..1..0..1..1..1....0..0..1..1..1..0..1..1....0..0..0..0..1..1..1..1
%K A232317 nonn
%O A232317 1,1
%A A232317 _R. H. Hardin_, Nov 22 2013