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.

A213100 G.f. satisfies: A(x) = 1 + x/A(-x*A(x)^9)^3.

Original entry on oeis.org

1, 1, 3, 24, 181, 1893, 20601, 245176, 3018669, 38198478, 493218343, 6441378129, 84807054552, 1120545910725, 14820493111536, 195812569428897, 2580287366558579, 33878771120862777, 443012040333754728, 5770422757461475027, 74931929672784252306
Offset: 0

Views

Author

Paul D. Hanna, Jun 05 2012

Keywords

Comments

Compare definition of g.f. to:
(1) B(x) = 1 + x/B(-x*B(x)) when B(x) = 1/(1-x).
(2) C(x) = 1 + x/C(-x*C(x)^3)^2 when C(x) = 1 + x*C(x)^2 (A000108).
(3) D(x) = 1 + x/D(-x*D(x)^5)^3 when D(x) = 1 + x*D(x)^3 (A001764).
(4) E(x) = 1 + x/E(-x*E(x)^7)^4 when E(x) = 1 + x*E(x)^4 (A002293).
(5) F(x) = 1 + x/F(-x*F(x)^9)^5 when F(x) = 1 + x*F(x)^5 (A002294).
The first negative term is a(68). - Georg Fischer, Feb 16 2019

Examples

			G.f.: A(x) = 1 + x + 3*x^2 + 24*x^3 + 181*x^4 + 1893*x^5 + 20601*x^6 +...
Related expansions:
A(x)^9 = 1 + 9*x + 63*x^2 + 516*x^3 + 4563*x^4 + 45207*x^5 + 486579*x^6 +...
A(-x*A(x)^9)^3 = 1 - 3*x - 15*x^2 - 64*x^3 - 798*x^4 - 8277*x^5 - 99411*x^6 -...
		

Crossrefs

Programs

  • Mathematica
    m = 21; A[] = 1; Do[A[x] = 1 + x/A[-x A[x]^9]^3 + O[x]^m, {m}];
    CoefficientList[A[x], x] (* Jean-François Alcover, Nov 06 2019 *)
  • PARI
    {a(n)=local(A=1+x+x*O(x^n));for(i=1,n,A=1+x/subst(A^3,x,-x*subst(A^9,x,x+x*O(x^n))) );polcoeff(A,n)}
    for(n=0,30,print1(a(n),", "))