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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A176413 a(n) = 19*3^n. 1
19, 57, 171, 513, 1539, 4617, 13851, 41553, 124659, 373977, 1121931, 3365793, 10097379, 30292137, 90876411, 272629233, 817887699, 2453663097, 7360989291, 22082967873, 66248903619, 198746710857, 596240132571, 1788720397713 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Since 19^3 = 3^3+10^3+18^3, the cube of any multiple of 19 can be written as the sum of three positive cubes: (19*k)^3 = (3*k)^3 + (10*k)^3 + (18*k)^3.

LINKS

Table of n, a(n) for n=0..23.

Index entries for linear recurrences with constant coefficients, signature (3).

FORMULA

G.f.: 19/(1-3*x). - R. J. Mathar, Aug 24 2011

MATHEMATICA

19*3^Range[0, 30] (* or *) NestList[3#&, 19, 30] (* Harvey P. Dale, Feb 03 2013 *)

PROG

(MAGMA) [19*3^n: n in [0..250]];

CROSSREFS

Subsequence of A023042.

Sequence in context: A125818 A093362 A251073 * A263336 A061973 A041702

Adjacent sequences:  A176410 A176411 A176412 * A176414 A176415 A176416

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Apr 17 2010

EXTENSIONS

Comment edited by Jon E. Schoenfield, Jun 20 2010

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 June 25 21:43 EDT 2019. Contains 324357 sequences. (Running on oeis4.)