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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A190955 a(n) = 10*a(n-1) + 5*a(n-2), with a(0)=0, a(1)=1. 3
0, 1, 10, 105, 1100, 11525, 120750, 1265125, 13255000, 138875625, 1455031250, 15244690625, 159722062500, 1673444078125, 17533051093750, 183697731328125, 1924642568750000, 20164914344140625, 211272356285156250, 2213548134572265625, 23191843127148437500 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..965

Index entries for linear recurrences with constant coefficients, signature (10,5).

FORMULA

a(n) = (1/60)*sqrt(30)*((5+sqrt(30))^n - (5-sqrt(30))^n). - Paolo P. Lava, Jun 01 2011

G.f.: x/(1 - 10*x - 5*x^2). - R. J. Mathar, Nov 21 2011

a(n+1) = Sum_{k=0..n} A099089(n,k)*5^k. - Philippe Deléham, Nov 21 2011

MATHEMATICA

LinearRecurrence[{10, 5}, {0, 1}, 50]

PROG

(PARI) x='x+O('x^30); concat([0], Vec(x/(1-10*x-5*x^2))) \\ G. C. Greubel, Jan 25 2018

(MAGMA) I:=[0, 1]; [n le 2 select I[n] else 10*Self(n-1) + 5*Self(n-2): n in [1..30]]; // G. C. Greubel, Jan 25 2018

CROSSREFS

Sequence in context: A077369 A068618 A096484 * A004343 A163166 A068767

Adjacent sequences:  A190952 A190953 A190954 * A190956 A190957 A190958

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, May 24 2011

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 September 20 01:58 EDT 2019. Contains 327207 sequences. (Running on oeis4.)