login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A170739 G.f.: (1+x)/(1-19*x). 50
1, 20, 380, 7220, 137180, 2606420, 49521980, 940917620, 17877434780, 339671260820, 6453753955580, 122621325156020, 2329805177964380, 44266298381323220, 841059669245141180, 15980133715657682420, 303622540597495965980, 5768828271352423353620, 109607737155696043718780 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (19).

FORMULA

a(n)= Sum_{k, 0<=k<=n} A097805(n,k)*(-1)^(n-k)*20^k. - Philippe Deléham, Dec 04 2009

a(0) = 1; for n>0, a(n) = 20*19^(n-1). - Vincenzo Librandi, Dec 05 2009

a(0) = 1, a(1) = 20; for n>1, a(n) = 19*a(n-1). - Vincenzo Librandi, Dec 05 2012

MATHEMATICA

Join[{1}, 20*19^Range[0, 25]] (* Vladimir Joseph Stephan Orlovsky, Jul 13 2011 *)

CoefficientList[Series[(1+x)/(1-19x), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 05.2012 *)

PROG

(MAGMA) [1] cat [20*19^(n-1): n in [1..20]]; // Vincenzo Librandi, Dec 05 2012

(PARI) a(n)=20*19^n\19 \\ Charles R Greathouse IV, Jul 01 2013

CROSSREFS

Sequence in context: A170605 A170653 A170701 * A218722 A158534 A171325

Adjacent sequences:  A170736 A170737 A170738 * A170740 A170741 A170742

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Dec 04 2009

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 21 19:18 EDT 2019. Contains 323444 sequences. (Running on oeis4.)