%I A028566
%S A028566 0,9,20,33,48,65,84,105,128,153,180,209,240,273,308,345,384,425,468,
%T A028566 513,560,609,660,713,768,825,884,945,1008,1073,1140,1209,1280,1353,
%U A028566 1428,1505,1584,1665,1748,1833,1920,2009,2100,2193,2288,2385
%N A028566 n(n+8).
%H A028566 P. De Geest, <a href="http://www.worldofnumbers.com/consemor.htm">Palindromic 
               Quasipronics of the form n(n+x)</a>
%F A028566 a(n)= (n+4)^2 -4^2 = n*(n+8), n>=0.
%F A028566 G.f.: x*(9-7*x)/(1-x)^3.
%F A028566 a(n)=2*n+a(n-1)+5 (with a(1)=0) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), 
               Nov 08 2009]
%e A028566 For n=2, a(2)=2*2+0+5=9; n=3, a(3)=2*3+9+5=20; n=4, a(4)=2*4+20+5=33 
               [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Nov 08 2009]
%p A028566 a:=n->sum(n,j=9..n): seq(a(n), n=8..53); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), 
               Feb 12 2007
%p A028566 with(finance):seq(add(cashflows([k, k, 7], 0 ), k=1..n), n=0..45); # 
               [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Dec 22 2008]
%t A028566 s=0;lst={s};Do[s+=n++ +9;AppendTo[lst, s], {n, 0, 6!, 2}];lst [From Vladimir 
               Orlovsky (4vladimir(AT)gmail.com), Nov 16 2008]
%o A028566 (Other) SAGE: [lucas_number2(2,n,7-n)-1 for n in xrange(3,49)]# [From 
               Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Mar 12 2009]
%Y A028566 a(n-4), n>=5, fourth column (used for the Brackett series of the hydrogen 
               atom) of triangle A120070.
%Y A028566 Sequence in context: A094196 A017497 A059108 this_sequence A147479 A146680 
               A143704
%Y A028566 Adjacent sequences: A028563 A028564 A028565 this_sequence A028567 A028568 
               A028569
%K A028566 nonn,new
%O A028566 0,2
%A A028566 Patrick De Geest (pdg(AT)worldofnumbers.com)