A248465 - OEIS

%I #4 Oct 06 2014 19:18:57

%S 26,144,1436,6040,21182,56782,138534,295078,589916,1082878,1900666,

%T 3161064,5083368,7857546,11844802,17344202,24892396,34927864,48224830,

%U 65403924,87536430,115449764,150581308,194049230,247712034,312987618

%N Number of length 4+2 0..n arrays with no three consecutive terms having the sum of any two elements equal to twice the third

%C Row 4 of A248461

%H R. H. Hardin, <a href="/A248465/b248465.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = -a(n-1) -a(n-2) +2*a(n-5) +3*a(n-6) +4*a(n-7) +3*a(n-8) +2*a(n-9) -3*a(n-11) -4*a(n-12) -6*a(n-13) -5*a(n-14) -5*a(n-15) +3*a(n-18) +2*a(n-19) +4*a(n-20) +a(n-21) -a(n-23) +2*a(n-25) +2*a(n-26) +5*a(n-27) +3*a(n-28) +5*a(n-29) -5*a(n-32) -3*a(n-33) -5*a(n-34) -2*a(n-35) -2*a(n-36) +a(n-38) -a(n-40) -4*a(n-41) -2*a(n-42) -3*a(n-43) +5*a(n-46) +5*a(n-47) +6*a(n-48) +4*a(n-49) +3*a(n-50) -2*a(n-52) -3*a(n-53) -4*a(n-54) -3*a(n-55) -2*a(n-56) +a(n-59) +a(n-60) +a(n-61)

%e Some solutions for n=6

%e ..2....0....4....4....3....3....1....2....3....1....4....4....2....3....1....5

%e ..6....4....0....1....5....2....6....2....1....0....6....1....3....3....4....6

%e ..2....6....3....1....5....3....0....1....0....6....1....1....2....4....3....0

%e ..5....6....2....3....6....5....1....6....1....4....5....6....5....1....6....4

%e ..6....3....6....1....1....0....1....0....4....1....0....3....1....5....6....3

%e ..6....6....3....4....2....1....4....2....0....1....4....5....2....2....2....6

%K nonn

%O 1,1

%A _R. H. Hardin_, Oct 06 2014