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A178671 5^n-5. 2
-4, 0, 20, 120, 620, 3120, 15620, 78120, 390620, 1953120, 9765620, 48828120, 244140620, 1220703120, 6103515620, 30517578120, 152587890620, 762939453120, 3814697265620, 19073486328120, 95367431640620, 476837158203120, 2384185791015620, 11920928955078120 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (6,-5).

FORMULA

a(n) = 5*a(n-1)+20, n>0.

G.f.: 4*(-1+6*x)/((5*x-1)*(x-1)). a(n) = 4*A104891(n-1), n>0. - R. J. Mathar, Jan 03 2011

a(n) = 6*a(n-1) - 5*a(n-2). - Vincenzo Librandi, Jan 25 2013

MATHEMATICA

5^Range[0, 50]-5 (* Vladimir Joseph Stephan Orlovsky, Feb 20 2011* )

PROG

(MAGMA) [5^n-5: n in [0..25]];

CROSSREFS

Cf. A178676 (5^n+5).

Sequence in context: A286032 A199933 A078630 * A179270 A246132 A229827

Adjacent sequences:  A178668 A178669 A178670 * A178672 A178673 A178674

KEYWORD

sign,easy

AUTHOR

Vincenzo Librandi, Dec 25 2010

STATUS

approved

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Last modified January 16 15:53 EST 2019. Contains 319195 sequences. (Running on oeis4.)