cp's OEIS Frontend

A248440 Number of length 7+2 0..n arrays with every three consecutive terms having the sum of some two elements equal to twice the third.

%I A248440 #6 Jul 23 2025 11:42:23
%S A248440 2,9,52,389,1014,2021,3200,5589,8218,11401,14696,18947,23274,27861,
%T A248440 32772,39481,46246,53633,61036,69369,77910,86569,95228,105879,116826,
%U A248440 127859,139132,150965,162798,175561,188324,203137,218098,233121,248604,265287
%N A248440 Number of length 7+2 0..n arrays with every three consecutive terms having the sum of some two elements equal to twice the third.
%C A248440 Row 7 of A248433
%H A248440 R. H. Hardin, <a href="/A248440/b248440.txt">Table of n, a(n) for n = 1..210</a>
%e A248440 Some solutions for n=6
%e A248440 ..4....2....1....3....3....6....5....1....4....5....1....6....3....2....4....2
%e A248440 ..0....0....0....2....4....4....3....2....2....1....0....5....4....3....2....6
%e A248440 ..2....4....2....4....5....5....1....3....0....3....2....4....5....4....6....4
%e A248440 ..4....2....1....3....3....3....5....1....4....2....1....3....3....2....4....5
%e A248440 ..0....3....0....2....4....1....3....2....2....4....0....5....4....0....5....3
%e A248440 ..2....4....2....1....5....2....4....0....6....3....2....1....2....1....6....4
%e A248440 ..1....2....4....3....3....3....5....4....4....2....4....3....3....2....4....2
%e A248440 ..3....3....6....5....4....4....3....2....2....1....6....5....4....0....2....0
%e A248440 ..5....4....2....4....5....5....4....0....3....3....5....4....5....4....6....1
%K A248440 nonn
%O A248440 1,1
%A A248440 _R. H. Hardin_, Oct 06 2014