A202966 - OEIS

%I #5 Mar 31 2012 12:36:53

%S 0,200,1936,9884,33736,90604,207184,421620,785504,1366876,2251016,

%T 3543320,5371856,7888384,11270788,15726488,21492408,28838244,38069472,

%U 49527504,63592532,80687412,101276728,125870512,155027684,189355324

%N Number of arrays of 6 integers in -n..n with sum zero and adjacent elements differing in absolute value

%C Row 4 of A202962

%H R. H. Hardin, <a href="/A202966/b202966.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) -3*a(n-4) +a(n-5) +a(n-6) +a(n-9) +a(n-10) -3*a(n-11) +2*a(n-14) -a(n-15)

%e Some solutions for n=5

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

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

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

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

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_ Dec 26 2011