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.

A232552 E.g.f. satisfies: A(x) = Sum_{n>=0} Integral( A(x)^n dx )^n/n!, where the constant of integration is zero.

Original entry on oeis.org

1, 1, 2, 9, 64, 630, 8030, 126247, 2371612, 52026293, 1309661828, 37318672196, 1190672836246, 42159850045181, 1644546319080848, 70233352188006641, 3266637689293293616, 164720219739258021686, 8969422973088951968070, 525585300443124229026511, 33039986976855724686082476
Offset: 0

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Author

Paul D. Hanna, Nov 26 2013

Keywords

Comments

Compare to the identity:
if G(x) = Sum_{n>=0} Integral( G(x)^t dx )^n/n!, then G(x)^t = 1/(1 - t*x).

Examples

			G.f.: A(x) = 1 + x + 2*x^2/2! + 9*x^3/3! + 64*x^4/4! + 630*x^5/5! + 8030*x^6/6! +...
Let B(n,x) = Integral( A(x)^n dx ) with B(n,0)=0, then
A(x) = 1 + B(1,x) + B(2,x)^2/2! + B(3,x)^3/3! + B(4,x)^4/4! + B(5,x)^5/5! +...
A'(x) = A(x) + A(x)^2*B(2,x) + A(x)^3*B(3,x)^2/2! + A(x)^4*B(4,x)^3/3! +...
where
B(1,x) = x + x^2/2! + 2*x^3/3! + 9*x^4/4! + 64*x^5/5! + 630*x^6/6! +...
B(2,x) = x + 2*x^2/2! + 6*x^3/3! + 30*x^4/4! + 224*x^5/5! + 2260*x^6/6! +...
B(3,x) = x + 3*x^2/2! + 12*x^3/3! + 69*x^4/4! + 552*x^5/5! + 5790*x^6/6! +...
B(4,x) = x + 4*x^2/2! + 20*x^3/3! + 132*x^4/4! + 1144*x^5/5! + 12600*x^6/6! +...
B(5,x) = x + 5*x^2/2! + 30*x^3/3! + 225*x^4/4! + 2120*x^5/5! + 24670*x^6/6! +...
B(6,x) = x + 6*x^2/2! + 42*x^3/3! + 354*x^4/4! + 3624*x^5/5! + 44700*x^6/6! +...
...
B(2,x)^2/2! = x^2/2! + 6*x^3/3! + 36*x^4/4! + 270*x^5/5! + 2604*x^6/6! +...
B(3,x)^3/3! = x^3/3! + 18*x^4/4! + 255*x^5/5! + 3600*x^6/6! + 54747*x^7/7! +...
B(4,x)^4/4! = x^4/4! + 40*x^5/5! + 1120*x^6/6! + 28140*x^7/7! + 693504*x^8/8! +...
B(5,x)^5/5! = x^5/5! + 75*x^6/6! + 3675*x^7/7! + 152250*x^8/8! + 5866245*x^9/9! +...
B(6,x)^6/6! = x^6/6! + 126*x^7/7! + 9912*x^8/8! + 634284*x^9/9! + 36483048*x^10/10! +...
		

Crossrefs

Cf. A234855.

Programs

  • PARI
    {a(n)=local(A=1+x);for(i=1,n,A=sum(m=0,n,intformal(A^m + x*O(x^n))^m/m!));n!*polcoeff(A,n)}
    for(n=0,20,print1(a(n),", "))

Formula

E.g.f. satisfies: A'(x) = Sum_{n>=1} A(x)^n * ( Integral A(x)^n dx )^(n-1)/(n-1)!.