A188184 - OEIS

%I #7 Mar 31 2012 12:36:11

%S 32,94,227,480,920,1636,2739,4370,6698,9926,14293,20076,27594,37212,

%T 49341,64444,83036,105690,133037,165772,204654,250510,304239,366814,

%U 439284,522780,618513,727782,851974,992568,1151137,1329352,1528984

%N Number of strictly increasing arrangements of 6 numbers in -(n+4)..(n+4) with sum zero

%C Row 6 of A188181

%H R. H. Hardin, <a href="/A188184/b188184.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n)=3*a(n-1)-2*a(n-2)-a(n-3)+2*a(n-5)-a(n-6)-a(n-7)+2*a(n-8)-a(n-10)-2*a(n-11)+3*a(n-12)-a(n-13).

%F Empirical: G.f. -x*(-32 +2*x -9*x^2 -19*x^3 -28*x^4 +x^5 +5*x^6 -17*x^7 +x^8 +10*x^9 +13*x^10 -23*x^11 +8*x^12) / ( (1+x) *(1+x+x^2) *(x^4+x^3+x^2+x+1) *(x-1)^6 ). - R. J. Mathar, Mar 26 2011

%e Some solutions for n=5

%e .-7...-9...-6...-4...-8...-7...-7...-6...-7...-6...-8...-9...-6...-6...-9...-8

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

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

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

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

%e ..9....6....5....4....8....8....7....7....6....7....9....5....7....8....7....8

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 23 2011