cp's OEIS Frontend

A188175 Number of strictly increasing arrangements of n numbers in -(n+1)..(n+1) with sum zero.

%I A188175 #10 Jul 22 2025 11:01:03
%S A188175 1,3,8,24,73,227,734,2430,8150,27718,95514,332578,1168261,4136477,
%T A188175 14749992,52925886,190973410,692583902,2523265494,9231352260,
%U A188175 33901898722,124940568222,461938289518,1713007181342,6369928427268,23747917426918
%N A188175 Number of strictly increasing arrangements of n numbers in -(n+1)..(n+1) with sum zero.
%C A188175 Column 3 of A188181.
%C A188175 Apparently a(n) = A046919(n+3) for 1 <= n <= 30. - _Georg Fischer_, Oct 24 2018
%H A188175 R. H. Hardin, <a href="/A188175/b188175.txt">Table of n, a(n) for n = 1..30</a>
%e A188175 Some solutions for n=5
%e A188175 .-6...-5...-3...-4...-6...-4...-5...-4...-5...-3...-5...-6...-6...-6...-6...-5
%e A188175 .-2...-1...-2...-3...-3...-2...-4...-3...-3...-2...-3...-1...-1...-3...-2...-3
%e A188175 ..0....0...-1...-1....0....0....0....0....0...-1....0....0....0....1....1....1
%e A188175 ..2....1....2....3....3....2....3....1....3....1....2....3....2....3....3....2
%e A188175 ..6....5....4....5....6....4....6....6....5....5....6....4....5....5....4....5
%Y A188175 Cf. A046919.
%K A188175 nonn
%O A188175 1,2
%A A188175 _R. H. Hardin_ Mar 23 2011