%I A074285
%S A074285 1,4,12,18,24,32,56,91,78,72,144,168,112,192,360,270,234,260,360,576,
%T A074285 384,288,672,868,434,560,960,720,720,768,992,1488,864,864,1872,1482,
%U A074285 760,1120,2352,1764,1344,1408,1584,2808,1872,1152,2880,3420,1767,2232
%N A074285 Sum of the divisors of n-th triangular number.
%H A074285 T. D. Noe, <a href="b074285.txt">Table of n, a(n) for n=1..1000</a>
%e A074285 a(4)=18 because sum of divisors of 4th triangular number(i.e. 10) is 
               1+2+5+10=18.
%t A074285 t[n_]:=n*(n+1)/2; f[n_]:=Plus@@Divisors[t[n]]; lst={};Do[AppendTo[lst,
               f[n]],{n,5!}];lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), 
               Oct 08 2009]
%Y A074285 Sequence in context: A047958 A111371 A078514 this_sequence A057311 A063679 
               A075867
%Y A074285 Adjacent sequences: A074282 A074283 A074284 this_sequence A074286 A074287 
               A074288
%K A074285 nonn
%O A074285 1,2
%A A074285 Shyam Sunder Gupta (guptass(AT)rediffmail.com), Sep 21 2002