cp's OEIS Frontend

A069423 Number of n X 3 binary arrays with a path of adjacent 1's and no path of adjacent 0's from top row to bottom row.

%I A069423 #15 Aug 23 2024 18:10:12
%S A069423 1,19,147,907,5149,28159,151331,806463,4280141,22670199,119955523,
%T A069423 634412111,3354416225,17734138519,93751306327,495600489243,
%U A069423 2619870168133,13849199313235,73209594712831,386999645945759,2045750897807901,10814208630415211,57165847109895879
%N A069423 Number of n X 3 binary arrays with a path of adjacent 1's and no path of adjacent 0's from top row to bottom row.
%H A069423 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (11,-41,64,-35,-13,25,-12,2).
%F A069423 a(n) = A069378(n) - 2 * A069403(n). - _Sean A. Irvine_, Aug 23 2024
%F A069423 G.f.: x*(2*x^7-10*x^6+23*x^5-18*x^4-5*x^3+21*x^2-8*x-1) / ((x-1)*(x^2-3*x+1)*(2*x^5-4*x^4+x^3+9*x^2-7*x+1)). - _Alois P. Heinz_, Aug 23 2024
%Y A069423 Cf. 2 X n A001047, n X 2 A034182, vertical path of 1 A069361-A069395, vertical paths of 0+1 A069396-A069416, vertical path of 1 not 0 A069417-A069428, no vertical paths A069429-A069447, no horizontal or vertical paths A069448-A069452.
%K A069423 nonn,easy
%O A069423 1,2
%A A069423 _R. H. Hardin_, Mar 22 2002
%E A069423 More terms from _Sean A. Irvine_, Aug 23 2024