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A167875 One third of product plus sum of three consecutive nonnegative integers; a(n)=(n+1)(n^2+2n+3)/3. 10

%I #26 Sep 08 2022 08:45:48

%S 1,4,11,24,45,76,119,176,249,340,451,584,741,924,1135,1376,1649,1956,

%T 2299,2680,3101,3564,4071,4624,5225,5876,6579,7336,8149,9020,9951,

%U 10944,12001,13124,14315,15576,16909,18316,19799,21360,23001,24724,26531

%N One third of product plus sum of three consecutive nonnegative integers; a(n)=(n+1)(n^2+2n+3)/3.

%C a(n) = ((n*(n+1)*(n+2))+(n+(n+1)+(n+2)))/3, n >= 0.

%C Equals A006527 without initial term 0: a(n) = A006527(n+1).

%C Binomial transform of A167876.

%C Inverse binomial transform of A080930.

%C a(n) = A007290(n+2)+n+1.

%C a(n) = A014820(n)/(n+1) for n > 0.

%C a(n) = A116731(n+2)-1.

%C a(n) = A033547(n+1)-n.

%C a(n) = A054602(n)/3.

%C a(n) = A086514(n+3)-2.

%C a(n) = A002061(n+1)+a(n-1) for n > 0.

%C a(n) = A005894(n)-a(n-1) for n > 0.

%C First bisection is A057813.

%C Second differences are in A004277.

%C a(n) = A177342(n)*(-1)+a(n-1)*5 with n>0. For n=8, a(8)=-A177342(8)+a(7)*5=-631+176*5=249. - _Bruno Berselli_, May 18 2010

%H Vincenzo Librandi, <a href="/A167875/b167875.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).

%F a(n) = (n^3+3*n^2+5*n+3)/3.

%F a(n) = 3*a(n-1)-3*a(n-2)+a(n-3)+2 for n > 3; a(0)=1, a(1)=4, a(2)=11, a(3)=24.

%F G.f.: (1+x^2)/(1-x)^4.

%F a(n) = SUM(A109613(k)*A005408(n-k): 0<=k<=n). - _Reinhard Zumkeller_, Dec 05 2009

%F a(n)-4*a(n-1)+6*a(n-2)-4*a(n-3)+a(n-4)=0 for n>3. - _Bruno Berselli_, May 26 2010

%e a(0) = (0*1*2+0+1+2)/3 = (0+3)/3 = 1.

%e a(1) = (1*2*3+1+2+3)/3 = (6+6)/3 = 4.

%e a(6)-4*a(5)+6*a(4)-4*a(3)+a(2) = 119-4*76+6*45-4*24+11 = 0. - _Bruno Berselli_, May 26 2010

%t Select[Table[(n*(n+1)*(n+2)+n+(n+1)+(n+2))/3,{n,0,5!}],IntegerQ[#]&] (* _Vladimir Joseph Stephan Orlovsky_, Dec 04 2010 *)

%t (Times@@#+Total[#])/3&/@Partition[Range[0,65],3,1] (* _Harvey P. Dale_, Mar 14 2011 *)

%o (Magma) [ (&*s + &+s)/3 where s is [n..n+2]: n in [0..42] ];

%o (PARI) a(n)=(n+1)*(n^2+2*n+3)/3 \\ _Charles R Greathouse IV_, Oct 07 2015

%Y Cf. A001477 (nonnegative integers),

%Y A006527 ((n^3+2*n)/3),

%Y A167876 (1, 3, 4, 2, 0, 0, 0, 0, ...),

%Y A080930,

%Y A007290 (2*C(n, 3)),

%Y A014820 ((1/3)*(n^2+2*n+3)*(n+1)^2),

%Y A116731,

%Y A033547 (n*(n^2+5)/3),

%Y A054602 (Sum_{d|3} phi(d)*n^(3/d)),

%Y A086514 ((n^3-6*n^2+14*n-6)/3),

%Y A002061 (n^2-n+1),

%Y A005894 (centered tetrahedral numbers),

%Y A057813 ((2*n+1)*(4*n^2+4*n+3)/3),

%Y A004277 (1 and the positive even numbers),

%Y A028387 (n+(n+1)^2),

%Y A166941, A166942, A166943.

%K nonn,easy

%O 0,2

%A _Klaus Brockhaus_, Nov 14 2009

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