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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A131098 Partial sums of A151798. 8
1, 3, 7, 11, 15, 19, 23, 27, 31, 35, 39, 43, 47, 51, 55, 59, 63, 67, 71, 75, 79, 83, 87, 91, 95, 99, 103, 107, 111, 115, 119, 123, 127, 131, 135, 139, 143, 147, 151, 155, 159, 163, 167, 171, 175, 179, 183, 187, 191, 195, 199, 203, 207, 211, 215, 219, 223, 227, 231, 235, 239 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

1 together with A004767. - Omar E. Pol, Feb 23 2014

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

David Applegate, The movie version

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

FORMULA

a(1) = 1, a(n) = 4*n - 5 for n >= 2. - Jaroslav Krizek, Aug 15 2009

G.f.: x*(x+2*x^2+1)/(x-1)^2. - R. J. Mathar, Dec 08 2010

EXAMPLE

g.f. = x + 3*x^2 + 7*x^3 + 11*x^4 + 15*x^5 + 19*x^6 + 23*x^7 + 27*x^8 + ...

MATHEMATICA

CoefficientList[Series[(x + 2 x^2 + 1)/(x - 1)^2, {x, 0, 80}], x] (* Vincenzo Librandi, Feb 25 2014 *)

PROG

(MAGMA) I:=[1, 3, 7]; [n le 3 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..70]]; // Vincenzo Librandi, Feb 25 2014

(PARI) A131098(n)=abs(4*n-5) \\ M. F. Hasler, Apr 27 2018

CROSSREFS

Cf. A151798, A004767.

Sequence in context: A172338 A189787 A004767 * A118894 A194397 A039957

Adjacent sequences:  A131095 A131096 A131097 * A131099 A131100 A131101

KEYWORD

nonn,easy

AUTHOR

Hans Isdahl, Sep 24 2007

EXTENSIONS

Edited by N. J. A. Sloane, Jun 29 2009

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 February 16 08:26 EST 2019. Contains 320159 sequences. (Running on oeis4.)