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 A052808 E.g.f.: -log(1-x+log(1-x)). 0
 0, 2, 5, 24, 169, 1572, 18208, 252676, 4088138, 75571648, 1571427096, 36304942704, 922615912656, 25577663099232, 768176940800592, 24845381066244288, 860979848497650768, 31825036424306681088, 1249895536243141292544, 51975908060575367916288 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Previous name was: A simple grammar. LINKS INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 770 FORMULA E.g.f.: -log(1-x+log(1-x)). - Michael Somos, Sep 21, 2002 a(n) ~ (n-1)! / (1-LambertW(1))^n. - Vaclav Kotesovec, Oct 01 2013 MAPLE spec := [S, {C=Cycle(Z), B=Union(C, Z), S=Cycle(B)}, labeled]: seq(combstruct[count](spec, size=n), n=0..20); MATHEMATICA With[{nn=30}, CoefficientList[Series[-Log[1-x+Log[1-x]], {x, 0, nn}], x] Range[ 0, nn]!] (* Harvey P. Dale, Mar 27 2013 *) PROG (PARI) a(n)=if(n<0, 0, n!*polcoeff(-log(1-x+log(1-x+x*O(x^n))), n)) CROSSREFS Sequence in context: A020124 A012249 A303108 * A137157 A025134 A076534 Adjacent sequences:  A052805 A052806 A052807 * A052809 A052810 A052811 KEYWORD easy,nonn AUTHOR encyclopedia(AT)pommard.inria.fr, Jan 25 2000 EXTENSIONS More terms from Harvey P. Dale, Mar 27 2013 New name, using e.g.f., by Vaclav Kotesovec, Oct 01 2013 STATUS approved

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Last modified May 27 02:54 EDT 2019. Contains 323597 sequences. (Running on oeis4.)