%I A067998
%S A067998 0,1,0,3,8,15,24,35,48,63,80,99,120,143,168,195,224,255,288,323,360,399,
               440,483,528,
%T A067998 575,624,675,728,783,840,899,960,1023,1088,1155,1224,1295,1368,1443,1520,
               1599,1680,
%U A067998 1763,1848,1935,2024,2115,2208,2303,2400,2499,2600,2703,2808,2915,3024,
               3135,3248,3363
%V A067998 0,-1,0,3,8,15,24,35,48,63,80,99,120,143,168,195,224,255,288,323,360,399,
               440,483,528,
%W A067998 575,624,675,728,783,840,899,960,1023,1088,1155,1224,1295,1368,1443,1520,
               1599,1680,
%X A067998 1763,1848,1935,2024,2115,2208,2303,2400,2499,2600,2703,2808,2915,3024,
               3135,3248,3363
%N A067998 n^2 - 2*n.
%F A067998 a(n) = A005563(n-2) = A005563(-n) = A000290(n-1)-1
%F A067998 G.f.: x(3x-1)/(1-x)^3; E.g.f.: e^x(x^2-x); - Paul Barry (pbarry(AT)wit.ie), 
               Mar 27 2007
%F A067998 a(n)=2*n+a(n-1)-5 (with a(1)=0) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), 
               Nov 08 2009]
%e A067998 For n=2, a(2)=2*2+0-5=-1; n=3, a(3)=2*3-1-5=0; n=4, a(4)=2*4+0-5=3 [From 
               Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Nov 08 2009]
%p A067998 a:=n->sum(binomial(n,1),j=3..n): seq(a(n), n=0..59); - Zerinvary Lajos 
               (zerinvarylajos(AT)yahoo.com), Feb 12 2007
%p A067998 a[0]:=0:a[1]:=1:for n from 2 to 63 do a[n]:=2*a[n-1]-a[n-2]-2 od: seq(-a[n], 
               n=1..63); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Feb 18 
               2008
%p A067998 with(combinat, fibonacci):seq(fibonacci(3, i)-2,i=-1..58); - Zerinvary 
               Lajos (zerinvarylajos(AT)yahoo.com), Mar 20 2008
%t A067998 Table[ n^2 - 2*n, {n, 0, 60} ]
%Y A067998 Essentially the same as A005563.
%Y A067998 Sequence in context: A147998 A131386 A164003 this_sequence A060615 A022451 
               A080181
%Y A067998 Adjacent sequences: A067995 A067996 A067997 this_sequence A067999 A068000 
               A068001
%K A067998 easy,sign
%O A067998 0,4
%A A067998 George E. Antoniou (george.antoniou(AT)montclair.edu), Feb 06 2002
%E A067998 Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Feb 08 
               2002