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A172078 a(n) = (16*n^3+3*n^2-13*n)/6. 7
0, 1, 19, 70, 170, 335, 581, 924, 1380, 1965, 2695, 3586, 4654, 5915, 7385, 9080, 11016, 13209, 15675, 18430, 21490, 24871, 28589, 32660, 37100, 41925, 47151, 52794, 58870, 65395, 72385, 79856, 87824, 96305, 105315, 114870, 124986, 135679 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

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

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

Inverse binomial transform of this sequence: 0, 1, 17, 16, 0, 0 (0 continued). - Bruno Berselli, Dec 14 2010

Principal diagonal of the convolution array A213835. - Clark Kimberling, Jul 04 2012

REFERENCES

E. Deza and M. M. Deza, Figurate numbers, World Scientific Publishing (2012), page 93. - Bruno Berselli, Feb 13 2014

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

B. Berselli, A description of the recursive method in Comments lines: website Matem@ticamente (in Italian), 2008.

Index to sequences related to pyramidal numbers

Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

FORMULA

a(n) = n*(n+1)*(16*n-13)/6.

G.f.: x*(1+15*x)/(1-x)^4. - Bruno Berselli, Dec 14 2010

a(n) = Sum_{i=0..n-1} (n-i)*(16*i+1), with a(0)=0. - Bruno Berselli, Feb 10 2014

MAPLE

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

MATHEMATICA

LinearRecurrence[{4, -6, 4, -1}, {0, 1, 19, 70}, 50] (* Vincenzo Librandi, Mar 01 2012 *)

PROG

(PARI) a(n)=n*(16*n^2+3*n-13)/6 \\ Charles R Greathouse IV, Oct 07 2015

CROSSREFS

Cf. A001107.

Cf. similar sequences listed in A237616.

Sequence in context: A007547 A217081 A010007 * A196136 A198002 A093350

Adjacent sequences:  A172075 A172076 A172077 * A172079 A172080 A172081

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Jan 25 2010

STATUS

approved

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Last modified March 25 00:01 EDT 2017. Contains 284035 sequences.