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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A021114 Expansion of 1/((1-x)(1-2x)(1-5x)(1-6x)). 1
1, 14, 131, 1036, 7497, 51450, 341167, 2209592, 14071013, 88494406, 551310123, 3409583268, 20966120449, 128339843282, 782754695399, 4760106416464, 28878529850205, 174860636120478, 1057111102343395 (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 (14,-65,112,-60).

FORMULA

a(0)=1, a(1)=14; for n>1, a(n) = 11*a(n-1) -30*a(n-2) +2^n -1. - Vincenzo Librandi, Jul 07 2013

a(0)=1, a(1)=14, a(2)=131, a(3)=1036; for n>2, a(n) = 14*a(n-1) -65*a(n-2) +112*a(n-3) -60*a(n-4). - Vincenzo Librandi, Jul 07 2013

a(n) = (3*6^(n+3) - 5^(n+4) + 5*2^(n+3) - 3)/60. [Yahia Kahloune, Jul 07 2013]

MATHEMATICA

CoefficientList[Series[1 / ((1 - x) (1 - 2 x) (1 - 5 x) (1 - 6 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 07 2013 *)

PROG

(MAGMA) I:=[1, 14, 131, 1036]; [n le 4 select I[n] else 14*Self(n-1)-65*Self(n-2)+112*Self(n-3)-60*Self(n-4): n in [1..25]]; /* or */ m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-2*x)*(1-5*x)*(1-6*x)))); // Vincenzo Librandi, Jul 07 2013

CROSSREFS

Sequence in context: A006565 A206207 A026936 * A113976 A022738 A017269

Adjacent sequences:  A021111 A021112 A021113 * A021115 A021116 A021117

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

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 18 00:09 EDT 2019. Contains 328135 sequences. (Running on oeis4.)