cp's OEIS Frontend

A248429 Number of length n+2 0..4 arrays with every three consecutive terms having the sum of some two elements equal to twice the third.

%I A248429 #7 Nov 08 2018 08:53:02
%S A248429 29,45,69,101,165,261,389,645,1029,1541,2565,4101,6149,10245,16389,
%T A248429 24581,40965,65541,98309,163845,262149,393221,655365,1048581,1572869,
%U A248429 2621445,4194309,6291461,10485765,16777221,25165829,41943045,67108869,100663301
%N A248429 Number of length n+2 0..4 arrays with every three consecutive terms having the sum of some two elements equal to twice the third.
%H A248429 R. H. Hardin, <a href="/A248429/b248429.txt">Table of n, a(n) for n = 1..210</a>
%F A248429 Empirical: a(n) = a(n-1) + 4*a(n-3) - 4*a(n-4).
%F A248429 Empirical g.f.: x*(29 + 16*x + 24*x^2 - 84*x^3) / ((1 - x)*(1 - 4*x^3)). - _Colin Barker_, Nov 08 2018
%e A248429 Some solutions for n=6:
%e A248429 ..1....2....2....2....0....4....1....2....1....2....4....0....2....4....0....2
%e A248429 ..3....4....3....1....4....0....0....4....3....4....3....2....0....2....1....4
%e A248429 ..2....3....1....3....2....2....2....3....2....0....2....4....4....0....2....0
%e A248429 ..1....2....2....2....0....1....4....2....1....2....1....3....2....4....0....2
%e A248429 ..0....4....0....1....4....3....3....1....3....4....0....2....3....2....4....1
%e A248429 ..2....0....4....0....2....2....2....0....2....3....2....1....4....0....2....3
%e A248429 ..4....2....2....2....0....1....4....2....1....2....1....3....2....4....0....2
%e A248429 ..3....4....0....1....4....3....3....1....0....1....3....2....3....2....1....1
%Y A248429 Column 4 of A248433.
%K A248429 nonn
%O A248429 1,1
%A A248429 _R. H. Hardin_, Oct 06 2014