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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A027929 T(n,2n-6), T given by A027926. 2
1, 2, 5, 13, 33, 79, 176, 365, 709, 1300, 2267, 3785, 6085, 9465, 14302, 21065, 30329, 42790, 59281, 80789, 108473, 143683, 187980, 243157, 311261, 394616, 495847, 617905, 764093, 938093, 1143994, 1386321, 1670065, 2000714 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 3..1000

Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).

FORMULA

a(n) = sum(binomial(n-k, 6-2k), k=0..3). - Len Smiley, Oct 20 2001

a(n) = (3600-3420*n+1684*n^2-525*n^3+115*n^4-15*n^5+n^6)/720. G.f.: x^3*(1-x+x^2)*(1-4*x+7*x^2-4*x^3+x^4)/(1-x)^7. - Colin Barker, May 01 2012

MATHEMATICA

CoefficientList[Series[(1 - x + x^2) (1 - 4 x + 7 x^2 - 4 x^3 + x^4)/(1 - x)^7, {x, 0, 40}], x] (* Vincenzo Librandi, Oct 18 2013 *)

CROSSREFS

Cf. A228074.

Sequence in context: A219230 A108890 A220739 * A001659 A088921 A005183

Adjacent sequences:  A027926 A027927 A027928 * A027930 A027931 A027932

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling

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 15 22:20 EST 2018. Contains 317252 sequences. (Running on oeis4.)