Search: id:A113502
Results 1-1 of 1 results found.

%I A113502
%S A113502 3,6,9,10,12,15,18,20,21,24,27,28,30,33,36,39,40,42,45,48,50,51,54,55,
%T A113502 56,57,60,63,66,69,70,72,75,78,80,81,84,87,90,91,93,96,99,100,102,105,
%U A113502 108,110,111,112,114,117,120,123,126,129,130,132,135,136,138,140,141
%N A113502 A number n is included if at least one of its divisors > 1 is a triangle 
               number (i.e. is of the form m(m+1)/2, m >= 2).
%C A113502 n is in the sequence if it is not a "triangle-free" positive integer.
%C A113502 a(n) = A088723(n)/2. - Ray Chandler (rayjchandler(AT)sbcglobal.net), 
               May 29 2008
%H A113502 Leroy Quet, <a href="http://www.prism-of-spirals.net/">Home Page</a> 
               (listed in lieu of email address)
%e A113502 12 is included because its divisors are 1, 2, 3, 4, 6 and 12, two of 
               which (3 and
%e A113502 6) are triangular numbers > 1.
%t A113502 v={};Do[If[b=Select[Divisors[n], #>1 && IntegerQ[(1+8#)^(1/2)]&]; b!={}, 
               AppendTo[v, n]], {n, 200}]; v (Firoozbakht)
%Y A113502 Cf. A112886, A000217, A013929.
%Y A113502 Sequence in context: A055632 A133006 A055264 this_sequence A061904 A111359 
               A085782
%Y A113502 Adjacent sequences: A113499 A113500 A113501 this_sequence A113503 A113504 
               A113505
%K A113502 nonn
%O A113502 1,1
%A A113502 Leroy Quet Jan 10 2006
%E A113502 More terms from Farideh Firoozbakht (mymontain(AT)yahoo.com), Jan 12 
               2006

Search completed in 0.001 seconds