cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A193264 E.g.f. A(x) satisfies: A(A(A(x))) = 2*x*A'(x) - A(x), where A(x) = Sum_{n>=1} a(n)*x^n, with a(1)=1, a(2)=2.

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%I A193264 #9 Dec 31 2012 17:44:58
%S A193264 1,2,18,324,9140,359460,18408600,1174201280,90423766800,8215991163000,
%T A193264 865420074120800,104218992780067440,14188585798246317120,
%U A193264 2163608674997595229040,366682177870608886473600,68611838511981521881152000,14093827998013078645611495680
%N A193264 E.g.f. A(x) satisfies: A(A(A(x))) = 2*x*A'(x) - A(x), where A(x) = Sum_{n>=1} a(n)*x^n, with a(1)=1, a(2)=2.
%H A193264 Paul D. Hanna, <a href="/A193264/b193264.txt">Table of n, a(n) for n = 1..150</a>
%F A193264 E.g.f. A(x) satisfies: A(A(A(x))) = Sum_{n>=1} (2*n-1)*a(n)*x^n.
%F A193264 a(n) = n*A193265(n-1).
%e A193264 E.g.f.: A(x) = x + 2*x^2/2! + 18*x^3/3! + 324*x^4/4! + 9140*x^5/5! + 359460*x^6/6! +...+ a(n)*x^n/n! +...
%e A193264 where
%e A193264 A(A(A(x))) = x + 6*x^2/2! + 90*x^3/3! + 2268*x^4/4! + 82260*x^5/5! + 3954060*x^6/6! +...+ (2*n-1)*a(n)*x^n/n! +...
%e A193264 which equals:
%e A193264 2*x*A'(x) - A(x) = x + 3*2*x^2/2! + 5*18*x^3/3! + 7*324*x^4/4! + 9*9140*x^5/5! +...
%o A193264 (PARI) {a(n)=local(A=x);if(n<1,0,if(n<=2,n,A=x+sum(m=2,n-1,a(m)*x^m/m!)+x*O(x^n);
%o A193264 n!*polcoeff(subst(A,x,subst(A,x,A))-2*x*A',n)/(2*n-4)))}
%Y A193264 Cf. A193265, A179420.
%K A193264 nonn
%O A193264 1,2
%A A193264 _Paul D. Hanna_, Jul 20 2011