login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A038376 a(n) = (n-3)*A006918(n)/2. 1
0, 0, 0, 0, 1, 5, 12, 28, 50, 90, 140, 220, 315, 455, 616, 840, 1092, 1428, 1800, 2280, 2805, 3465, 4180, 5060, 6006, 7150, 8372, 9828, 11375, 13195, 15120, 17360, 19720, 22440, 25296, 28560, 31977, 35853, 39900, 44460, 49210, 54530, 60060, 66220, 72611 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,6

REFERENCES

K. B. Reid and L. W. Beineke "Tournaments", pp. 169-204 in L. W. Beineke and R. J. Wilson, editors, Selected Topics in Graph Theory, Academic Press, NY, 1978, p. 186 Theorem 6.11.

LINKS

Colin Barker, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (2,2,-6,0,6,-2,-2,1).

FORMULA

From Colin Barker, Nov 19 2016: (Start)

a(n) = (n^4-3*n^3-4*n^2+12*n)/48 for n even.

a(n) = (n^4-3*n^3-n^2+3*n)/48 for n odd.

a(n) = 2*a(n-1) + 2*a(n-2) - 6*a(n-3) + 6*a(n-5) - 2*a(n-6) - 2*a(n-7) + a(n-8) for n>7.

G.f.: x^4*(1+3*x) / ((1-x)^5 * (1+x)^3)

(End)

PROG

(PARI) concat(vector(4), Vec(x^4*(1+3*x) / ((1-x)^5 * (1+x)^3) + O(x^100))) \\ Colin Barker, Nov 19 2016

CROSSREFS

Sequence in context: A145768 A162778 A160807 * A002767 A055245 A196410

Adjacent sequences:  A038373 A038374 A038375 * A038377 A038378 A038379

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

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 December 5 05:13 EST 2021. Contains 349530 sequences. (Running on oeis4.)