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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A167566 The third left hand column of triangle A167565. 4
2, 16, 67, 202, 497, 1064, 2058, 3684, 6204, 9944, 15301, 22750, 32851, 46256, 63716, 86088, 114342, 149568, 192983, 245938, 309925, 386584, 477710, 585260, 711360, 858312, 1028601, 1224902, 1450087, 1707232, 1999624, 2330768, 2704394 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,1

LINKS

G. C. Greubel, Table of n, a(n) for n = 3..1000

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

FORMULA

From Johannes W. Meijer, Nov 23 2009: (Start)

a(n) = (7*n^5 - 30*n^4 + 45*n^3 - 30*n^2 + 8*n)/5!.

G.f.: (1*z^2 + 4*z + 2)/(1-z)^6.

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).

a(n) - 5*a(n-1) + 10*a(n-2) - 10*a(n-3) + 5*a(n-4) - a(n-5) = 7. (End)

a(n) = A024166(n-2) + A000389(n+2). - J. M. Bergot, Jul 04 2017

MATHEMATICA

Table[(7*n^5 - 30*n^4 + 45*n^3 - 30*n^2 + 8*n)/5!, {n, 3, 100}] (* or *) LinearRecurrence[{6, -15, 20, -15, 6, -1}, {2, 16, 67, 202, 497, 1064}, 100] (* G. C. Greubel, Jun 16 2016 *)

PROG

(PARI) Vec((1*z^2 + 4*z + 2)/(1-z)^6 + O(z^50)) \\ Michel Marcus, Jul 05 2017

(PARI) a(n) = n*(7*n^4 - 30*n^3 + 45*n^2 - 30*n + 8)/120 \\ Charles R Greathouse IV, Jul 14 2017

CROSSREFS

Equals the third left hand column of triangle A167565.

Other left hand columns are A000027, A000292, A167567 and A168304.

Sequence in context: A110048 A094505 A035598 * A034579 A006733 A034580

Adjacent sequences:  A167563 A167564 A167565 * A167567 A167568 A167569

KEYWORD

easy,nonn

AUTHOR

Johannes W. Meijer, Nov 10 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 April 22 11:46 EDT 2019. Contains 322330 sequences. (Running on oeis4.)