cp's OEIS Frontend

A188238 Number of nondecreasing arrangements of 5 numbers in -(n+3)..(n+3) with sum zero and not more than two numbers equal.

%I A188238 #8 Apr 27 2018 08:53:37
%S A188238 58,119,221,374,598,903,1317,1852,2540,3397,4459,5744,7296,9133,11303,
%T A188238 13830,16766,20135,23997,28378,33342,38919,45177,52148,59908,68489,
%U A188238 77971,88392,99836,112341,125999,140850,156990,174463,193369,213754,235726
%N A188238 Number of nondecreasing arrangements of 5 numbers in -(n+3)..(n+3) with sum zero and not more than two numbers equal.
%C A188238 Row 5 of A188236.
%H A188238 R. H. Hardin, <a href="/A188238/b188238.txt">Table of n, a(n) for n = 1..200</a>
%F A188238 Empirical: a(n) = 2*a(n-1) - a(n-3) - 2*a(n-5) + 2*a(n-6) + a(n-8) - 2*a(n-10) + a(n-11).
%F A188238 Empirical g.f.: x*(58 + 3*x - 17*x^2 - 10*x^3 - 31*x^4 + 44*x^5 + 7*x^6 + 20*x^7 - 13*x^8 - 37*x^9 + 22*x^10) / ((1 - x)^5*(1 + x)^2*(1 + x^2)*(1 + x + x^2)). - _Colin Barker_, Apr 27 2018
%e A188238 Some solutions for n=4:
%e A188238 .-4...-4...-7...-3...-7...-5...-5...-7...-3...-4...-4...-6...-5...-3...-4...-5
%e A188238 .-2...-3...-1...-1...-6...-3...-2...-6...-3...-2...-1...-4...-1...-2...-4...-1
%e A188238 .-2...-3....1....0....1....0...-1....1...-1...-1....1....3...-1...-1....1....0
%e A188238 ..4....3....2....1....5....3....1....6....1....1....2....3....0....0....3....0
%e A188238 ..4....7....5....3....7....5....7....6....6....6....2....4....7....6....4....6
%Y A188238 Cf. A188236.
%K A188238 nonn
%O A188238 1,1
%A A188238 _R. H. Hardin_, Mar 24 2011