Search: id:A080956 Results 1-1 of 1 results found. %I A080956 %S A080956 1,1,0,2,5,9,14,20,27,35,44,54,65,77,90,104,119,135,152,170,189,209,230, %T A080956 252,275,299,324,350,377,405,434,464,495,527,560,594,629,665,702,740, %U A080956 779,819,860,902,945,989,1034,1080,1127,1175,1224,1274,1325,1377,1430 %V A080956 1,1,0,-2,-5,-9,-14,-20,-27,-35,-44,-54,-65,-77,-90,-104,-119,-135,-152, -170,-189,-209, %W A080956 -230,-252,-275,-299,-324,-350,-377,-405,-434,-464,-495,-527,-560,-594, -629,-665,-702, %X A080956 -740,-779,-819,-860,-902,-945,-989,-1034,-1080,-1127,-1175,-1224,-1274, -1325,-1377 %N A080956 (n+1)(2-n)/2. %C A080956 Coefficient of x in the polynomial C(n,0)+C(n+1,1)x+C(n+2,2)x(x-1)/2. %C A080956 Equals A154990 * [1,2,3,...]. [From Gary W. Adamson & Mats Granvik (qntmpkt(AT)yahoo.com), Jan 19 2009] %F A080956 a(n) = 2(C(n+1, 1)-C(n+2, 2)) = (n+1)(2-n)/2 %F A080956 If we define f(n,i,a)=sum(binomial(n,k)*stirling1(n-k,i)*product(-a-j, j=0..k-1),k=0..n-i), then a(n) = f(n,n-1,2), for n>=3. [From Milan R. Janjic (agnus(AT)blic.net), Dec 20 2008] %F A080956 E.g.f.: exp(x)*(1-x^2/2) . [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 05 2009, R. J. Mathar, Jun 11 2009] %F A080956 G.f.: (1-2*x)/(1-x)^3. [R. J. Mathar, (mathar(AT)strw.leidenuniv.nl), Jun 11 2009] %p A080956 seq(-sum(k-1, k=3..n), n=0..53); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jan 28 2008 %p A080956 a[0]:=0:a[1]:=1:for n from 2 to 54 do a[n]:=2*a[n-1]-a[n-2]-1 od: seq(a[n], n=1..54); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Feb 18 2008 %p A080956 restart: G(x):=exp(x)*(x-x^2/2): f[0]:=G(x): for n from 1 to 54 do f[n]:=diff(f[n-1], x) od: x:=0: seq(f[n],n=1..54 );# [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 05 2009] %Y A080956 Cf. A000096. %Y A080956 A154990 [From Gary W. Adamson & Mats Granvik (qntmpkt(AT)yahoo.com), Jan 19 2009] %Y A080956 Sequence in context: A132315 A132336 A000096 this_sequence A132337 A134189 A109470 %Y A080956 Adjacent sequences: A080953 A080954 A080955 this_sequence A080957 A080958 A080959 %K A080956 easy,sign %O A080956 0,4 %A A080956 Paul Barry (pbarry(AT)wit.ie), Mar 01 2003 %E A080956 Adapted Lajos e.g.f. to offset zero R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 11 2009 Search completed in 0.001 seconds