cp's OEIS Frontend

A188239 Number of nondecreasing arrangements of 6 numbers in -(n+4)..(n+4) with sum zero and not more than two numbers equal.

%I A188239 #10 Apr 27 2018 10:29:37
%S A188239 245,527,1019,1818,3047,4859,7435,10994,15791,22121,30323,40782,53931,
%T A188239 70257,90301,114662,143999,179037,220565,269444,326607,393061,469893,
%U A188239 558272,659449,774765,905649,1053624,1220309,1407423,1616785,1850320
%N A188239 Number of nondecreasing arrangements of 6 numbers in -(n+4)..(n+4) with sum zero and not more than two numbers equal.
%C A188239 Row 6 of A188236.
%H A188239 R. H. Hardin, <a href="/A188239/b188239.txt">Table of n, a(n) for n = 1..200</a>
%F A188239 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 A188239 Empirical g.f.: x*(245 - 208*x - 72*x^2 + 60*x^3 + 158*x^4 - 117*x^5 - 39*x^6 + 188*x^7 - 42*x^8 - 140*x^9 - 110*x^10 + 263*x^11 - 98*x^12) / ((1 - x)^6*(1 + x)*(1 + x + x^2)*(1 + x + x^2 + x^3 + x^4)). - _Colin Barker_, Apr 27 2018
%e A188239 Some solutions for n=4:
%e A188239 .-8...-7...-7...-6...-4...-8...-4...-7...-5...-7...-4...-6...-7...-5...-7...-7
%e A188239 .-2...-6...-6...-4...-4...-4...-4...-6...-3...-4...-3...-5...-6...-2...-1...-7
%e A188239 .-1...-1...-6...-4...-1...-2....0...-6...-1...-1...-2...-4...-4...-2....0...-2
%e A188239 ..3...-1....6....3...-1....4....1....5....1....2...-1....3....5....1....1....4
%e A188239 ..3....7....6....3....4....4....2....7....2....5....4....5....6....3....1....5
%e A188239 ..5....8....7....8....6....6....5....7....6....5....6....7....6....5....6....7
%Y A188239 Cf. A188236.
%K A188239 nonn
%O A188239 1,1
%A A188239 _R. H. Hardin_, Mar 24 2011