cp's OEIS Frontend

A248458 Number of length n+2 0..5 arrays with no three consecutive terms having the sum of any two elements equal to twice the third.

%I A248458 #6 Jul 23 2025 11:43:39
%S A248458 174,862,4272,21182,105026,520788,2582406,12805334,63497776,314866606,
%T A248458 1561330890,7742183252,38391228334,190370917646,943993962960,
%U A248458 4680991358518,23211674211122,115099939580084,570747116572614
%N A248458 Number of length n+2 0..5 arrays with no three consecutive terms having the sum of any two elements equal to twice the third.
%C A248458 Column 5 of A248461
%H A248458 R. H. Hardin, <a href="/A248458/b248458.txt">Table of n, a(n) for n = 1..210</a>
%F A248458 Empirical: a(n) = 3*a(n-1) +10*a(n-2) +11*a(n-3) -32*a(n-4) -119*a(n-5) -139*a(n-6) -26*a(n-7) +126*a(n-8) +130*a(n-9) +28*a(n-10) -12*a(n-11) -4*a(n-12)
%e A248458 Some solutions for n=5
%e A248458 ..0....0....0....0....4....4....4....2....3....3....4....0....3....4....1....4
%e A248458 ..2....4....1....0....4....0....2....4....2....0....1....3....1....1....0....4
%e A248458 ..0....5....0....4....3....5....5....2....0....2....5....4....4....1....3....0
%e A248458 ..2....4....3....0....4....0....1....2....5....0....5....4....5....4....5....4
%e A248458 ..2....1....0....0....4....5....5....3....1....3....0....0....2....1....5....3
%e A248458 ..4....1....1....4....5....1....0....2....2....0....0....3....2....3....0....4
%e A248458 ..4....2....3....3....4....4....3....5....2....4....3....4....3....3....3....4
%K A248458 nonn
%O A248458 1,1
%A A248458 _R. H. Hardin_, Oct 06 2014