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A064752
a(n) = n*6^n - 1.
6
5, 71, 647, 5183, 38879, 279935, 1959551, 13436927, 90699263, 604661759, 3990767615, 26121388031, 169789022207, 1097098297343, 7052774768639, 45137758519295, 287753210560511, 1828079220031487, 11577835060199423
OFFSET
1,1
FORMULA
a(n) = 13*a(n-1) - 48*a(n-2) + 36*a(n-3); a(1)=5, a(2)=71, a(3)=647. - Harvey P. Dale, May 25 2011
G.f.: 6*x/(1-6*x)^2+x/(x-1). - Harvey P. Dale, May 25 2011
MATHEMATICA
Table[n 6^n-1, {n, 25}] (* or *) LinearRecurrence[{13, -48, 36}, {5, 71, 647}, 25] (* Harvey P. Dale, May 25 2011 *)
PROG
(Magma) [ n*6^n-1: n in [1..20]]; // Vincenzo Librandi, Sep 16 2011
CROSSREFS
Sequence in context: A295536 A197427 A197668 * A033507 A092250 A362159
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Oct 19 2001
STATUS
approved