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A060352
a(n) = n*3^n - 1.
8
2, 17, 80, 323, 1214, 4373, 15308, 52487, 177146, 590489, 1948616, 6377291, 20726198, 66961565, 215233604, 688747535, 2195382770, 6973568801, 22082967872, 69735688019, 219667417262, 690383311397, 2165293113020
OFFSET
1,1
LINKS
FORMULA
G.f.: x*(2-3*x)*(1+3*x)/((1-x)*(1-3*x)^2). - Colin Barker, Apr 22 2012
a(n) = 7*a(n-1) - 15*a(n-2) + 9*a(n-3), a(1)=2, a(2)=17, a(3)=80. - Harvey P. Dale, Dec 14 2012
E.g.f.: 1 + exp(x)*(3*exp(2*x)*x - 1). - Stefano Spezia, Jan 05 2020
MATHEMATICA
Table[n*3^n-1, {n, 50}] (* Vladimir Joseph Stephan Orlovsky, May 19 2011 *)
LinearRecurrence[{7, -15, 9}, {2, 17, 80}, 50] (* Harvey P. Dale, Dec 14 2012 *)
PROG
(PARI) { for (n=1, 200, write("b060352.txt", n, " ", n*3^n - 1); ) } \\ Harry J. Smith, Jul 04 2009
CROSSREFS
Cf. A060353.
Sequence in context: A235471 A297411 A183175 * A215185 A002523 A360747
KEYWORD
nonn,easy
AUTHOR
Jason Earls, Mar 31 2001
STATUS
approved