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!)
A140063 Binomial transform of [1, 3, 7, 0, 0, 0,...]. 1
1, 4, 14, 31, 55, 86, 124, 169, 221, 280, 346, 419, 499, 586, 680, 781, 889, 1004, 1126, 1255, 1391, 1534, 1684, 1841, 2005, 2176, 2354, 2539, 2731, 2930, 3136, 3349, 3569, 3796, 4030, 4271, 4519, 4774, 5036 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..39.

Derek Kinsella, Plane division by lines and circles

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

FORMULA

A007318 * [1, 3, 7, 0, 0, 0,...].

O.g.f.: x*(1+x+5x^2)/(1-x)^3. - R. J. Mathar, May 06 2008

a(n) = 7*n^2/2-15*n/2+5 = 3*a(n-1)-3*a(n-2)+a(n-3). - R. J. Mathar, Jul 31 2009

a(n)=a(n-1)+7*n-11 (with a(1)=1) [From Vincenzo Librandi, Nov 24 2010]

EXAMPLE

a(4) = 31 = (1, 3, 3, 1) dot (1, 3, 7, 0) = (1 + 9 + 21 + 0).

MATHEMATICA

s = 1; lst = {s}; Do[s += n + 2; AppendTo[lst, s], {n, 1, 265, 7}]; lst - Zerinvary Lajos, Jul 11 2009

PROG

(PARI) a(n)=n*(7*n-15)/2+5 \\ Charles R Greathouse IV, Jun 17 2017

CROSSREFS

Sequence in context: A049451 A079776 A117109 * A051409 A072475 A001740

Adjacent sequences:  A140060 A140061 A140062 * A140064 A140065 A140066

KEYWORD

nonn,easy

AUTHOR

Gary W. Adamson, May 03 2008

EXTENSIONS

More terms from R. J. Mathar, May 06 2008

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 19 03:53 EST 2017. Contains 294912 sequences.