%I A032765
%S A032765 0,1,2,5,8,11,16,21,26,33,40,47,56,65,74,85,96,107,120,133,146,161,176,
%T A032765 191,208,225,242,261,280,299,320,341,362,385,408,431,456,481,506,533,
%U A032765 560,587,616,645,674,705,736,767,800,833,866,901,936,971,1008
%N A032765 Floor[ n(n+1)(n+2) / n+(n+1)+(n+2) ].
%C A032765 Satisfies a(n+1) -2*a(n) + a(n-1) = (2/3)(1+w^(n+1)+w^(2n+2)), a(0)=0 
               & a(1)=1 where w is the imaginary cubic root of unity. - Robert G. 
               Wilson v (rgwv(AT)rgwv.com), Jun 24 2002
%C A032765 First differences have this pattern: (+1) +1 +1 +3 +3 +3 +5 +5 +5 +7 
               +7 +7 +9 +9 +9 - Alexandre Wajnberg (alexandre.wajnberg(AT)skynet.be), 
               Dec 19 2005
%H A032765 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               KobonTriangle.html">Kobon Triangle</a>
%F A032765 n^2 - ceil[n(n-1)/3]. G.f.: [x(1+2x^2-x^3)]/[(1+x+x^2)(1-x)^3]. - R. 
               Stephan, May 05 2004
%F A032765 a(n) = Floor [n(n+2)/3]. - Saburo Tamura, sent by Alexandre Wajnberg 
               (alexandre.wajnberg(AT)skynet.be), Dec 19 2005
%t A032765 Table[ Floor[ n(n + 1)(n + 2)/(n + (n + 1) + (n + 2))], {n, 0, 55}]
%Y A032765 Cf. A001082, A032766.
%Y A032765 Sequence in context: A163249 A088366 A130258 this_sequence A154484 A129300 
               A107679
%Y A032765 Adjacent sequences: A032762 A032763 A032764 this_sequence A032766 A032767 
               A032768
%K A032765 nonn
%O A032765 0,3
%A A032765 Patrick De Geest (pdg(AT)worldofnumbers.com), May 15, 1998.