# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a332547 Showing 1-1 of 1 %I A332547 #17 Jul 16 2024 14:30:33 %S A332547 1,1,1,1,3,3,1,3,5,5,3,3,7,7,5,1,9,9,5,15,11,11,3,15,13,13,21,7,15,15, %T A332547 1,11,17,17,21,9,19,19,15,5,21,21,11,33,23,23,3,21,35,25,39,13,27,45, %U A332547 35,21,29,29,15,15,31,31,21,13,55,33,17,51,35,35 %N A332547 a(n) = largest odd divisor d < n of n*(n+1)/2. %C A332547 Used by _Michael J. Collins_ in the analysis of A082183 and A082184. %H A332547 Hugo Pfoertner, Table of n, a(n) for n = 1..10000 %t A332547 Join[{1},Table[Select[Divisors[(n(n+1))/2],OddQ[#]&&#