The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A060783 Number of conics which pass through 3 points and are bitangent to a general curve of order n. 1
 0, 0, 4, 36, 132, 340, 720, 1344, 2296, 3672, 5580, 8140, 11484, 15756, 21112, 27720, 35760, 45424, 56916, 70452, 86260, 104580, 125664, 149776, 177192, 208200, 243100, 282204, 325836, 374332, 428040, 487320, 552544, 624096, 702372, 787780, 880740, 981684, 1091056 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Harry J. Smith, Table of n, a(n) for n=0..1000 H. Brocard and T. Lemoyne, Courbes géométriques remarquables (courbes spéciales) Planes et Gauches, Tome I, Paris: Albert Blanchard, 1967 [First publ. 1919]; see p. 411. J. Steiner, Aufgaben und Lehrsätze, Journal für die reine und angewandte Mathematik, Zeitschriftenband (1855), Vol. 49, p. 273. Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1). FORMULA a(n) = (n-1)*n*(n^2 + 3*n - 6)/2. G.f.: 4*x^2*(1+4*x-2*x^2)/(1-x)^5. - Colin Barker, Mar 26 2012 E.g.f.: exp(x)*x^2*(4 + 8*x + x^2)/2. - Stefano Spezia, Jul 13 2024 MATHEMATICA Table[(n-1)n (n^2+3n-6)/2, {n, 0, 40}] (* Harvey P. Dale, Apr 05 2020 *) PROG (PARI) { for (n=0, 1000, write("b060783.txt", n, " ", (n-1)*n*(n^2 + 3*n - 6)/2); ) } \\ Harry J. Smith, Jul 11 2009 CROSSREFS Sequence in context: A318150 A275133 A374387 * A296948 A125756 A173961 Adjacent sequences: A060780 A060781 A060782 * A060784 A060785 A060786 KEYWORD nonn,easy AUTHOR Antreas P. Hatzipolakis (xpolakis(AT)otenet.gr), Apr 28 2001 EXTENSIONS More terms from Jason Earls, Apr 29 2001 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 7 05:36 EDT 2024. Contains 375008 sequences. (Running on oeis4.)