cp's OEIS Frontend

A190072 Number of arrangements of 3 nonzero numbers x(i) in -n..n with the sum of div(x(i),x(i+1)), where div(a,b)=a/b produces the integer quotient implying a nonnegative remainder, equal to zero.

%I A190072 #7 Nov 17 2022 19:11:41
%S A190072 4,12,36,76,143,233,366,536,760,1028,1363,1751,2221,2758,3387,4096,
%T A190072 4907,5804,6819,7931,9174,10525,12021,13631,15401,17299,19366,21572,
%U A190072 23959,26490,29220,32114,35210,38476,41963,45629,49527,53618,57953,62489,67285
%N A190072 Number of arrangements of 3 nonzero numbers x(i) in -n..n with the sum of div(x(i),x(i+1)), where div(a,b)=a/b produces the integer quotient implying a nonnegative remainder, equal to zero.
%C A190072 Row 2 of A190071.
%H A190072 R. H. Hardin, <a href="/A190072/b190072.txt">Table of n, a(n) for n = 1..200</a>
%e A190072 Some solutions for n=4
%e A190072 .-1....1....4...-2...-1....1...-3...-4...-2...-1...-1....2...-4...-3....3....1
%e A190072 ..3...-1...-4...-4....1....3...-3...-3....3...-3...-1....2...-2....4...-3...-1
%e A190072 ..2...-3...-4....4....1....4....3....2....2....4....1...-2....1....4...-4...-2
%Y A190072 Cf. A190071.
%K A190072 nonn
%O A190072 1,1
%A A190072 _R. H. Hardin_, May 04 2011