This site is supported by donations to The OEIS Foundation.

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A052803 E.g.f.: -1/(2*log(1-x))*(1-(1+4*log(1-x))^(1/2)). 2
 1, 1, 5, 44, 566, 9674, 207166, 5343456, 161405016, 5591409720, 218592034584, 9521490534720, 457329182411856, 24014921905589328, 1368772939062117936, 84161443919543331840, 5553011951023694408064, 391360838810043628416384 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Previous name was: A simple grammar. LINKS INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 762 FORMULA E.g.f.: (1/2)/log(-1/(-1+x))*(1-(1-4*log(-1/(-1+x)))^(1/2)). a(n) ~ 2*sqrt(2) * n^(n-1) / (exp(3*n/4) * (exp(1/4)-1)^(n-1/2)). - Vaclav Kotesovec, Sep 30 2013 a(n) = sum((2k)!/(k+1)! * |stirling1(n,k)|, k=0..n). - Michael D. Weiner, Dec 23 2014 MAPLE spec := [S, {C=Cycle(Z), S=Sequence(B), B=Prod(C, S)}, labeled]: seq(combstruct[count](spec, size=n), n=0..20); MATHEMATICA CoefficientList[Series[-1/(2*Log[1-x]) * (1-(1+4*Log[1-x])^(1/2)), {x, 0, 20}], x]* Range[0, 20]! (* Vaclav Kotesovec, Sep 30 2013 *) CROSSREFS Sequence in context: A195242 A243697 A106273 * A201923 A222059 A252931 Adjacent sequences:  A052800 A052801 A052802 * A052804 A052805 A052806 KEYWORD easy,nonn AUTHOR encyclopedia(AT)pommard.inria.fr, Jan 25 2000 EXTENSIONS New name using e.g.f., Vaclav Kotesovec, Sep 30 2013 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.