A110286 a(n) = 15*2^n.

15, 30, 60, 120, 240, 480, 960, 1920, 3840, 7680, 15360, 30720, 61440, 122880, 245760, 491520, 983040, 1966080, 3932160, 7864320, 15728640, 31457280, 62914560, 125829120, 251658240, 503316480, 1006632960, 2013265920, 4026531840, 8053063680, 16106127360

Offset

0,1

Comments

The first differences are the sequence itself. Doubling the terms gives the same sequence (beginning one step further).

References

William Dunham, Journey Through Genius, Wiley, 1990, Chapter 3, p. 65.

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..235

Tanya Khovanova, Recursive Sequences

Index entries for linear recurrences with constant coefficients, signature (2).

Formula

G.f.: 15/(1-2x). - Philippe Deléham, Nov 23 2008

a(n) = A000079(n)*15 = A007283(n)*5 = A020714(n)*3. - Omar E. Pol, Dec 17 2008

a(n) = A173787(n+4,n). - Reinhard Zumkeller, Feb 28 2010

Subsequence of A051916. - Reinhard Zumkeller, Mar 20 2010

a(n) = 2*a(n-1) (with a(0)=15). - Vincenzo Librandi, Dec 26 2010

E.g.f.: 15*exp(2*x). - Stefano Spezia, May 15 2021

Mathematica

15*2^Range[0, 60] (* Vladimir Joseph Stephan Orlovsky, Jun 09 2011 *)
(* Alternative: *)
NestList[2#&, 15, 30] (* Harvey P. Dale, Oct 19 2014 *)

Prog

(Magma) [15*2^n: n in [0..40]]; // Vincenzo Librandi, Apr 28 2011
(PARI) a(n)=15<<n \\ Charles R Greathouse IV, Oct 07 2015

Crossrefs

Cf. A007283, A020714, A005009, A005010, A005015, A005029.

Cf. A000079, A051916, A173787.

Sequence in context: A190715 A217744 A115811 * A254859 A127526 A249764

Adjacent sequences: A110283 A110284 A110285 * A110287 A110288 A110289

Keyword

easy,nonn,changed

Author

Alexandre Wajnberg, Sep 07 2005

Extensions

Edited by Omar E. Pol, Dec 16 2008

Status

approved