%I A140672
%S A140672 0,8,19,33,50,70,93,119,148,180,215,253,294,338,385,435,488,544,603,665,
%T A140672 730,798,869,943,1020,1100,1183,1269,1358,1450,1545,1643,1744,1848,1955,
%U A140672 2065,2178,2294,2413,2535,2660,2788,2919,3053
%N A140672 n(3n+13)/2.
%F A140672 a(n)=(3*n^2 + 13*n)/2.
%F A140672 a(n)=3*n+a(n-1)+2 (with a(1)=0) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), 
               Nov 08 2009]
%e A140672 For n=2, a(2)=3*2+0+2=8; n=3, a(3)=3*3+8+2=19; n=4, a(4)=3*4+19+2=33 
               [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Nov 08 2009]
%p A140672 with(finance):seq(add(cashflows([2,k,n], 0 ),k=3..n),n=2..45); - Zerinvary 
               Lajos (zerinvarylajos(AT)yahoo.com), Jun 22 2008
%t A140672 s=0;lst={s};Do[s+=n++ +8;AppendTo[lst, s], {n, 0, 6!, 3}];lst [From Vladimir 
               Orlovsky (4vladimir(AT)gmail.com), Nov 16 2008]
%Y A140672 Cf. A000326, A005449, A045943, A115067, A140090, A140091, A059845, A140673, 
               A140674, A140675.
%Y A140672 The generalized pentagonal numbers b*n+3*n*(n-1)/2, for b = 1 through 
               12, form sequences A000326, A005449, A045943, A115067, A140090, A140091, 
               A059845, A140672, A140673, A140674, A140675, A151542.
%Y A140672 Sequence in context: A017485 A146270 A146222 this_sequence A135027 A158916 
               A045557
%Y A140672 Adjacent sequences: A140669 A140670 A140671 this_sequence A140673 A140674 
               A140675
%K A140672 easy,nonn,new
%O A140672 0,2
%A A140672 Omar E. Pol (info(AT)polprimos.com), May 22 2008