A183940 - OEIS

%I #5 Mar 31 2012 12:35:55

%S 1,1,11,39,497,2343,22881,177535,1682939,14821961,149400849,

%T 1447662427,14866001809,149548074379,1531694916059,15535552043969,

%U 159929685546853,1644687110377919,17107437074253385,178041145616880947

%N Number of strings of n numbers x(i) in -5..5 with sums of x(i) and of x(i)*x(i+1) both zero

%C Column 5 of A183944

%H R. H. Hardin, <a href="/A183940/b183940.txt">Table of n, a(n) for n = 1..21</a>

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,3

%A _R. H. Hardin_ Jan 08 2011