A213111 E.g.f.: A(x) = exp( x/A(-x*A(x)^6)^2 ).
1, 1, 5, 73, 1497, 48321, 2016733, 106687113, 6745180529, 495988880833, 41495596689141, 3880618840698249, 400537444634948041, 45126092520882513921, 5501154522933362385485, 720279890636684703825481, 100658531630809161730405857, 14934726665907895887483076737
Offset: 0
Keywords
Examples
E.g.f.: A(x) = 1 + x + 5*x^2/2! + 73*x^3/3! + 1497*x^4/4! + 48321*x^5/5! +... Related expansions: A(x)^2 = 1 + 2*x + 12*x^2/2! + 176*x^3/3! + 3728*x^4/4! + 118912*x^5/5! +... A(x)^6 = 1 + 6*x + 60*x^2/2! + 1008*x^3/3! + 23952*x^4/4! + 775296*x^5/5! +... 1/A(-x*A(x)^6)^2 = 1 + 2*x + 20*x^2/2! + 296*x^3/3! + 7824*x^4/4! +... The logarithm of the e.g.f., log(A(x)) = x/A(-x*A(x)^6)^2, begins: log(A(x)) = x + 4*x^2/2! + 60*x^3/3! + 1184*x^4/4! + 39120*x^5/5! + 1639872*x^6/6! +...
Programs
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PARI
{a(n)=local(A=1+x);for(i=1,n,A=exp(x/subst(A^2,x,-x*A^6+x*O(x^n))));n!*polcoeff(A,n)} for(n=0,25,print1(a(n),", "))
Comments