A202510 - OEIS

%I #7 Mar 31 2012 12:36:48

%S 1,7,57,297,1785,11015,68781,436919,2782455,17852623,114949893,

%T 742430377,4811939259,31282061157,203951966061,1333111663347,

%U 8732654184777,57311401737559,376739449264935,2480070264283519,16347300910687523

%N Number of zero-sum -7..7 arrays of n elements with first through third differences also in -7..7

%C Column 7 of A202511

%H R. H. Hardin, <a href="/A202510/b202510.txt">Table of n, a(n) for n = 1..100</a>

%e Some solutions for n=7

%e ..7....5...-4....3...-2....5....1....7....7...-2...-6....5....1...-5...-1....5

%e ..3....4...-1....0....4...-1....5....6....5....1...-2....2...-3...-7....2....0

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

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

%e .-6....0....2...-1...-5...-3...-1...-7...-3...-1...-1...-4....4....7....0....2

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

%e ..3...-7...-3....4....1....3...-7....1...-7...-1....5....4...-2...-1...-5...-5

%K nonn

%O 1,2

%A _R. H. Hardin_ Dec 20 2011