A178672 a(n) = 6^n - 6.

0, 30, 210, 1290, 7770, 46650, 279930, 1679610, 10077690, 60466170, 362797050, 2176782330, 13060694010, 78364164090, 470184984570, 2821109907450, 16926659444730, 101559956668410, 609359740010490, 3656158440062970, 21936950640377850, 131621703842267130

Offset

1,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (7,-6).

Formula

a(n) = 6*a(n-1) + 30, n>1.

From R. J. Mathar, Jan 05 2011: (Start)

a(n) = 30*A003464(n-1).

G.f.: 30*x^2 / ( (1-6*x)*(1-x) ). (End)

a(n) = 7*a(n-1) - 6*a(n-2). - Vincenzo Librandi, Jan 25 2013

E.g.f.: exp(6*x) - 6*exp(x) + 5. - G. C. Greubel, Jan 27 2019

Mathematica

6^Range[30]- 6 (* Vincenzo Librandi, Jan 25 2013 *)
LinearRecurrence[{7, -6}, {0, 30}, 30] (* Harvey P. Dale, Jul 25 2020 *)

Prog

(Magma) [6^n-6: n in [1..30]]
(PARI) vector(30, n, 6^n-6) \\ G. C. Greubel, Jan 27 2019
(Sage) [6^n-6 for n in (1..30)] # G. C. Greubel, Jan 27 2019
(GAP) List([1..30], n -> 6^n-6); # G. C. Greubel, Jan 27 2019

Crossrefs

Cf. A003464.

Sequence in context: A347828 A069965 A215627 * A061661 A042754 A215192

Adjacent sequences: A178669 A178670 A178671 * A178673 A178674 A178675

Keyword

nonn,easy

Author

Vincenzo Librandi, Dec 25 2010

Status

approved