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

 

Logo

Invitation: celebrating 50 years of OEIS, 250000 sequences, and Sloane's 75th, there will be a conference at DIMACS, Rutgers, Oct 9-10 2014.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A021284 Expansion of 1/((1-x)(1-2x)(1-9x)(1-10x)). 1
1, 22, 335, 4400, 53481, 620202, 6970675, 76624900, 828512861, 8845504382, 93498427815, 980374738200, 10212261530641, 105799242660562, 1091082072825755, 11208627544304300, 114766536787594821 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index to sequences with linear recurrences with constant coefficients, signature (22,-149,308,-180)

FORMULA

a(n) = (7*10^(n+3) - 9^(n+4) + 9*2^(n+3) - 7)/504. - Yahia Kahloune, Jul 08 2013

a(0)=1, a(1)=22, a(2)=335, a(3)=4400; for n>3, a(n) = 22*a(n-1) -149*a(n-2) +308*a(n-3) -180*a(n-4). - Vincenzo Librandi, Jul 08 2013

a(0)=1, a(1)=22; for n>1 a(n) = 19*a(n-1) -90*a(n-2) +2^n -1. - Vincenzo Librandi, Jul 08 2013

MATHEMATICA

CoefficientList[Series[1 / ((1 - x) (1 - 2 x) (1 - 9 x) (1 - 10 x)), {x, 0, 20}], x] (* Vincenzo Librandi Jul 08 2013 *)

PROG

(MAGMA) I:=[1, 22, 335, 4400]; [n le 4 select I[n] else 22*Self(n-1)-149*Self(n-2)+308*Self(n-3)-180*Self(n-4): n in [1..25]]; /* or */ m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-2*x)*(1-9*x)*(1-10*x)))); // Vincenzo Librandi, Jul 08 2013

CROSSREFS

Sequence in context: A216730 A048795 A068186 * A019623 A021794 A223812

Adjacent sequences:  A021281 A021282 A021283 * A021285 A021286 A021287

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 | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified July 26 03:04 EDT 2014. Contains 244924 sequences.