login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A221904 9^n + 10^n. 1
2, 19, 181, 1729, 16561, 159049, 1531441, 14782969, 143046721, 1387420489, 13486784401, 131381059609, 1282429536481, 12541865828329, 122876792454961, 1205891132094649, 11853020188851841 (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 (19,-90).

FORMULA

G.f.: 1/(1 - 9*x) + 1/(1 - 10*x).

E.g.f.: exp(9*x) + exp(10*x).

a(n) = 19*a(n-1) - 90*a(n-2), a(1)=2, a(2)=19.

MATHEMATICA

CoefficientList[Series[1/(1-9*x) + 1/(1-10*x), {x, 0, 30}], x]

LinearRecurrence[{19, -90}, {2, 19}, 30] (* Harvey P. Dale, Nov 10 2017 *)

PROG

(MAGMA) [9^n + 10^n: n in [0..30]];

CROSSREFS

Cf. A007689, A074611, A074615, A074619, A074622, A074624, A155872.

Sequence in context: A037742 A037637 A163067 * A124262 A140781 A128970

Adjacent sequences:  A221901 A221902 A221903 * A221905 A221906 A221907

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Feb 06 2013

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 October 20 10:00 EDT 2020. Contains 337900 sequences. (Running on oeis4.)