A248533 - OEIS

%I #9 Nov 08 2018 19:06:21

%S 101,113,125,137,149,173,197,221,245,293,341,389,437,533,629,725,821,

%T 1013,1205,1397,1589,1973,2357,2741,3125,3893,4661,5429,6197,7733,

%U 9269,10805,12341,15413,18485,21557,24629,30773,36917,43061,49205,61493,73781

%N Number of length n+3 0..4 arrays with every four consecutive terms having the sum of some three elements equal to three times the fourth.

%H R. H. Hardin, <a href="/A248533/b248533.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) + 2*a(n-4) - 2*a(n-5).

%F Empirical g.f.: x*(101 + 12*x + 12*x^2 + 12*x^3 - 190*x^4) / ((1 - x)*(1 - 2*x^4)). - _Colin Barker_, Nov 08 2018

%e Some solutions for n=6:

%e ..1....3....1....2....3....0....4....4....4....2....1....2....1....0....2....2

%e ..2....1....0....4....2....3....2....2....2....4....1....2....0....3....2....1

%e ..4....0....1....3....3....3....3....1....2....1....0....3....3....2....0....1

%e ..1....0....2....3....0....2....3....1....0....1....2....1....0....3....4....4

%e ..1....3....1....2....3....0....0....4....4....2....1....2....1....0....2....2

%e ..2....1....0....0....2....3....2....2....2....0....1....2....0....3....2....1

%e ..0....0....1....3....3....3....3....1....2....1....0....3....3....2....0....1

%e ..1....0....2....3....4....2....3....1....0....1....2....1....0....3....4....0

%e ..1....3....1....2....3....0....0....4....4....2....1....2....1....0....2....2

%Y Column 4 of A248537.

%K nonn

%O 1,1

%A _R. H. Hardin_, Oct 08 2014