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

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A050927 Number of directed multigraphs with loops on 3 nodes with n arcs. 4
 1, 2, 10, 31, 90, 222, 520, 1090, 2180, 4090, 7356, 12660, 21105, 34020, 53460, 81891, 122826, 180510, 260746, 370370, 518518, 715870, 976170, 1315470, 1753975, 2314936, 3027224, 3923845, 5044920, 6436200, 8152542, 10255896 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS FORMULA G.f.: (x^10+3*x^8+10*x^7+16*x^6+12*x^5+16*x^4+10*x^3+3*x^2+1) / ((1-x^3)^3*(1-x^2)^4*(1-x)^2). MATHEMATICA < 1/(1 - x^i), {i, 1, n^2 - n}], {x, 0, nn}], x] (* Geoffrey Critzer, Aug 07 2015 *) CoefficientList[Series[(x^10 + 3 x^8 + 10 x^7 + 16 x^6 + 12 x^5 + 16 x^4 + 10 x^3 + 3 x^2 + 1)/((1 - x^3)^3 (1 - x^2)^4 (1 - x)^2), {x, 0, 33}], x] (* Vincenzo Librandi, Aug 08 2015 *) CROSSREFS Cf. A005993, A138107. Sequence in context: A193008 A024456 A197452 * A197302 A263782 A011921 Adjacent sequences:  A050924 A050925 A050926 * A050928 A050929 A050930 KEYWORD easy,nonn AUTHOR Vladeta Jovovic, Dec 30 1999 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.

Last modified January 23 16:48 EST 2020. Contains 331173 sequences. (Running on oeis4.)