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A221098 E.g.f. satisfies: A(x) = Sum_{n>=0} log(1 + x*A(x)^(4*n))^n/n!. 3

%I #3 Jan 01 2013 21:23:48

%S 1,1,8,156,5184,243280,14742240,1097403552,97012667136,9936480419424,

%T 1157549828855040,151193318253405120,21890302973632558080,

%U 3480525852596442818688,603034041051994953483264,113109668528001746742489600,22839699845167989485088522240

%N E.g.f. satisfies: A(x) = Sum_{n>=0} log(1 + x*A(x)^(4*n))^n/n!.

%F E.g.f. also satisfies:

%F (1) A(x) = Sum_{n>=0} binomial(A(x)^(4*n), n) * x^n.

%F (2) A(x) = Sum_{n>=0} x^n * Sum_{k=0..n} Stirling1(n,k) * A(x)^(4*n*k)/n!.

%e E.g.f.: A(x) = 1 + x + 8*x^2/2! + 156*x^3/3! + 5184*x^4/4! + 243280*x^5/5! +...

%e where A(x) satisfies:

%e A(x) = 1 + log(1 + x*A(x)^4) + log(1 + x*A(x)^8)^2/2! + log(1 + x*A(x)^12)^3/3! +...

%e The e.g.f. also satisfies:

%e A(x) = 1 + A(x)^4*x + A(x)^8*(A(x)^8-1)*x^2/2! + A(x)^12*(A(x)^12-1)*(A(x)^12-2)*x^3/3! + A(x)^16*(A(x)^16-1)*(A(x)^16-2)*(A(x)^16-3)*x^4/4! +...+ binomial(A(x)^(4*n), n)*x^n +...

%o (PARI) {a(n)=local(A=1+x); for(i=1, n, A=sum(m=0, n, log(1+x*(A+x*O(x^n))^(4*m))^m/m!)); n!*polcoeff(A, n)}

%o for(n=0,20,print1(a(n),", "))

%o (PARI) {a(n)=local(A=1+x); for(i=1, n, A=sum(m=0, n, binomial((A+x*O(x^n))^(4*m), m)*x^m)); n!*polcoeff(A, n)}

%o for(n=0,20,print1(a(n),", "))

%o (PARI) {Stirling1(n, k)=n!*polcoeff(binomial(x, n), k)}

%o {a(n)=local(A=1+x); for(i=1, n, A=sum(m=0, n, sum(k=0, m, Stirling1(m, k)*(A+x*O(x^n))^(4*m*k))*x^m/m!)); n!*polcoeff(A, n)}

%o for(n=0,20,print1(a(n),", "))

%Y Cf. A189981, A221096, A221097, A221099.

%K nonn

%O 0,3

%A _Paul D. Hanna_, Jan 01 2013

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Last modified April 25 13:24 EDT 2024. Contains 371971 sequences. (Running on oeis4.)