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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A096943 Sixth column of (1,5)-Pascal triangle A096940. 2
5, 26, 81, 196, 406, 756, 1302, 2112, 3267, 4862, 7007, 9828, 13468, 18088, 23868, 31008, 39729, 50274, 62909, 77924, 95634, 116380, 140530, 168480, 200655, 237510, 279531, 327236, 381176, 441936, 510136, 586432, 671517, 766122, 871017, 987012 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

If Y is a 5-subset of an n-set X then, for n>=9, a(n-9) is the number of 5-subsets of X having at most one element in common with Y. - Milan Janjic, Dec 08 2007

LINKS

Table of n, a(n) for n=0..35.

Index entries for linear recurrences with constant coefficients, signature (6, -15, 20, -15, 6, -1).

FORMULA

G.f.: (5-4*x)/(1-x)^6.

a(n)= (n+25)*binomial(n+4, 4)/5 = 5*b(n)-4*b(n-1), with b(n):= A000389(n+5)=binomial(n+5, 5).

a(0)=5, a(1)=26, a(2)=81, a(3)=196, a(4)=406, a(5)=756, a(n)=6*a(n-1)- 15*a(n-2)+20*a(n-3)-15*a(n-4)+6*a(n-5)-a(n-6). - Harvey P. Dale, Jan 11 2014

MATHEMATICA

CoefficientList[Series[(5-4x)/(1-x)^6, {x, 0, 40}], x] (* or *) LinearRecurrence[ {6, -15, 20, -15, 6, -1}, {5, 26, 81, 196, 406, 756}, 40] (* Harvey P. Dale, Jan 11 2014 *)

CROSSREFS

Fifth column: A096942; seventh column: A096944.

Sequence in context: A081530 A254831 A145013 * A166810 A210367 A261347

Adjacent sequences:  A096940 A096941 A096942 * A096944 A096945 A096946

KEYWORD

nonn,easy

AUTHOR

Wolfdieter Lang, Jul 16 2004

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 March 29 07:21 EDT 2017. Contains 284250 sequences.