%I A050409
%S A050409 0,5,29,86,190,355,595,924,1356,1905,2585,3410,4394,5551,6895,8440,
%T A050409 10200,12189,14421,16910,19670,22715,26059,29716,33700,38025,42705,
%U A050409 47754,53186,59015,65255,71920,79024,86581,94605,103110,112110,121619
%N A050409 Truncated square pyramid numbers: a(n)=sum(k^2,k=n..2*n).
%F A050409 a(n)=(1/6)*n*(n+1)*(14*n+1)
%F A050409 a(n) = A132121(n,4) for n>3. - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               Aug 12 2007
%p A050409 seq(add((n+k)^2,k=0..n),n=0..37); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), 
               Dec 01 2006
%p A050409 with(finance):seq(add(cashflows([n*k,k^2,0],3)*16, k=0..n), n=0..45); 
               - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jul 16 2008
%Y A050409 Cf. A000330, A033994, A132124, A132112.
%Y A050409 Sequence in context: A100559 A087348 A154412 this_sequence A111937 A139856 
               A097345
%Y A050409 Adjacent sequences: A050406 A050407 A050408 this_sequence A050410 A050411 
               A050412
%K A050409 easy,nice,nonn
%O A050409 0,2
%A A050409 Klaus Strassburger (strass(AT)ddfi.uni-duesseldorf.de), Dec 22 1999