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A213807 a(n)=Sum(L(i)*L(j)*L(k), 0<=i<j<k<=n), where L(m) is the m-th Lucas number A000032(m). 2
0, 0, 6, 50, 295, 1450, 6706, 29790, 129900, 559680, 2395701, 10212620, 43430140, 184412740, 782337466, 3317046390, 14059122315, 59576034630, 252422169726, 1069418901650, 4530501461200, 19192481509300, 81303194179081, 344412501233400, 1458972161656920 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

This is to Lucas numbers A000032 as A213787 is to Fibonacci numbers A000045.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..500

FORMULA

G.f.: -(x^6-19*x^5+4*x^4+53*x^3+7*x^2-8*x-6)*x^2 / ((x-1) * (x+1) * (x^2-x-1) * (x^2+x-1)*(x^2+4*x-1)*(x^2-3*x+1)). - Alois P. Heinz, Jun 21 2012

MAPLE

a:= n-> (Matrix(10, (i, j)-> `if`(i=j-1, 1, `if`(i=10,

         [-1, -1, 16, -3, -51, 24, 45, -27, -8, 7][j], 0)))^(n+3).

         <<-20, 1, 0, 0, 0, 6, 50, 295, 1450, 6706>>)[1, 1]:

seq (a(n), n=0..30);  # Alois P. Heinz, Jun 21 2012

CROSSREFS

Cf. A000032, A213787.

Sequence in context: A138422 A001303 A220887 * A241781 A272469 A223816

Adjacent sequences:  A213804 A213805 A213806 * A213808 A213809 A213810

KEYWORD

nonn,easy

AUTHOR

Jonathan Vos Post, Jun 20 2012

STATUS

approved

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Last modified June 19 17:16 EDT 2019. Contains 324222 sequences. (Running on oeis4.)