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

 

Logo

Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A008725 Molien series for 3-dimensional group [2,n] = *22n. 5
1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 15, 17, 19, 21, 24, 27, 30, 33, 36, 39, 42, 46, 50, 54, 58, 62, 66, 70, 75, 80, 85, 90, 95, 100, 105, 111, 117, 123, 129, 135, 141, 147, 154, 161, 168, 175, 182, 189, 196, 204, 212, 220, 228, 236, 244, 252, 261, 270, 279, 288, 297, 306 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 190

Index entries for Molien series

Index entries for linear recurrences with constant coefficients, signature (2,-1,0,0,0,0,1,-2,1).

FORMULA

G.f.: 1/(1-x)^2/(1-x^7).

a(n) = sum(floor(j/7), {j,0,n+7}), a(n-7) = (1/2)floor(n/7)*(2n-5 -7*floor(n/7)). - Mitch Harris, Sep 08 2008

a(n) = +2*a(n-1) -a(n-2) +a(n-7) -2*a(n-8) +a(n-9). - R. J. Mathar, Apr 20 2010

MAPLE

1/(1-x)^2/(1-x^7): seq(coeff(series(%, x, n+1), x, n), n=0..80);

MATHEMATICA

s=0; lst={}; Do[AppendTo[lst, s+=n]; AppendTo[lst, s+=n]; AppendTo[lst, s+=n]; AppendTo[lst, s+=n]; AppendTo[lst, s+=n]; AppendTo[lst, s+=n]; AppendTo[lst, s+=n], {n, 0, 5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Mar 14 2010 *)

CoefficientList[Series[1 / (1 - x)^2 / (1 - x^7), {x, 0, 70}], x] (* Vincenzo Librandi, Jun 11 2013 *)

LinearRecurrence[{2, -1, 0, 0, 0, 0, 1, -2, 1}, {1, 2, 3, 4, 5, 6, 7, 9, 11}, 70] (* Harvey P. Dale, Sep 27 2014 *)

CROSSREFS

Sequence in context: A281613 A174738 A011867 * A275673 A026445 A279078

Adjacent sequences:  A008722 A008723 A008724 * A008726 A008727 A008728

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Vladimir Joseph Stephan Orlovsky, Mar 14 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified November 18 14:06 EST 2017. Contains 294892 sequences.