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A172078 a(n) = (16*n^3+3*n^2-13*n)/6. 7

%I

%S 0,1,19,70,170,335,581,924,1380,1965,2695,3586,4654,5915,7385,9080,

%T 11016,13209,15675,18430,21490,24871,28589,32660,37100,41925,47151,

%U 52794,58870,65395,72385,79856,87824,96305,105315,114870,124986,135679

%N a(n) = (16*n^3+3*n^2-13*n)/6.

%C Generated by the formula n*(n+1)*(2*d*n-(2*d-3))/6 for d=8.

%C In fact, the sequence is related to A001107 by a(n) = n*A001107(n) - Sum_{k=0..n-1} A001107(k), and this is the case d=8 in the identity n*(n*(d*n-d+2)/2) - Sum_{k=0..n-1} k*(d*k-d+2)/2 = n*(n+1)*(2*d*n-2*d+3)/6. - _Bruno Berselli_, Dec 14 2010

%C Inverse binomial transform of this sequence: 0, 1, 17, 16, 0, 0 (0 continued). - _Bruno Berselli_, Dec 14 2010

%C Principal diagonal of the convolution array A213835. - _Clark Kimberling_, Jul 04 2012

%D E. Deza and M. M. Deza, Figurate numbers, World Scientific Publishing (2012), page 93. - _Bruno Berselli_, Feb 13 2014

%H Vincenzo Librandi, <a href="/A172078/b172078.txt">Table of n, a(n) for n = 0..1000</a>

%H B. Berselli, A description of the recursive method in Comments lines: website <a href="http://www.lanostra-matematica.org/2008/12/sequenze-numeriche-e-procedimenti.html">Matem@ticamente</a> (in Italian), 2008.

%H <a href="/index/Ps#pyramidal_numbers">Index to sequences related to pyramidal numbers</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*(n+1)*(16*n-13)/6.

%F G.f.: x*(1+15*x)/(1-x)^4. - _Bruno Berselli_, Dec 14 2010

%F a(n) = Sum_{i=0..n-1} (n-i)*(16*i+1), with a(0)=0. - _Bruno Berselli_, Feb 10 2014

%p A172078:=n->(16*n^3+3*n^2-13*n)/6: seq(A172078(n), n=0..50); # _Wesley Ivan Hurt_, Jan 21 2017

%t LinearRecurrence[{4,-6,4,-1}, {0, 1, 19, 70}, 50] (* _Vincenzo Librandi_, Mar 01 2012 *)

%o (PARI) a(n)=n*(16*n^2+3*n-13)/6 \\ _Charles R Greathouse IV_, Oct 07 2015

%Y Cf. A001107.

%Y Cf. similar sequences listed in A237616.

%K nonn,easy

%O 0,3

%A _Vincenzo Librandi_, Jan 25 2010

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Last modified March 19 00:26 EDT 2019. Contains 321305 sequences. (Running on oeis4.)