cp's OEIS Frontend

A188240 Number of nondecreasing arrangements of 7 numbers in -(n+5)..(n+5) with sum zero and not more than two numbers equal.

%I A188240 #7 Jul 22 2025 11:04:27
%S A188240 1082,2395,4818,8964,15696,26123,41748,64370,96346,140463,200176,
%T A188240 279520,383424,517461,688344,903624,1172142,1503785,1910034,2403502,
%U A188240 2998722,3711609,4560190,5564140,6745632,8128589,9739838,11608268,13765902
%N A188240 Number of nondecreasing arrangements of 7 numbers in -(n+5)..(n+5) with sum zero and not more than two numbers equal.
%C A188240 Row 7 of A188236
%H A188240 R. H. Hardin, <a href="/A188240/b188240.txt">Table of n, a(n) for n = 1..200</a>
%F A188240 Empirical: a(n)=2*a(n-1)-a(n-3)-a(n-5)+a(n-6)-2*a(n-7)+2*a(n-8)+a(n-9)-a(n-13)-2*a(n-14)+2*a(n-15)-a(n-16)+a(n-17)+a(n-19)-2*a(n-21)+a(n-22)
%e A188240 Some solutions for n=4
%e A188240 .-6...-7...-9...-8...-7...-5...-8...-9...-4...-8...-6...-6...-6...-8...-9...-7
%e A188240 .-4...-5...-9...-6...-6...-5...-5...-8...-3...-7...-6...-5...-6...-8...-5...-7
%e A188240 .-2...-2....1...-3...-2...-1...-5...-8...-3...-3....0...-5...-3...-1...-1...-4
%e A188240 .-1....0....3...-1...-1...-1....0....3...-1...-1....0....1....1...-1....0...-1
%e A188240 ..1....3....3....1...-1....1....5....6....2....6....1....2....1....4....2....6
%e A188240 ..5....3....5....8....8....5....6....8....3....6....3....5....5....6....6....6
%e A188240 ..7....8....6....9....9....6....7....8....6....7....8....8....8....8....7....7
%K A188240 nonn
%O A188240 1,1
%A A188240 _R. H. Hardin_ Mar 24 2011