login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A141358
E.g.f.: A(x) = exp(x*A(x)^3*exp(x^2*A(x)^6*exp(x^3*A(x)^9*exp(x^4*A(x)^12*exp(...))))), an infinite power tower.
4
1, 1, 7, 106, 2509, 80956, 3313579, 164514904, 9608077945, 645470256592, 49038954301711, 4157529546929056, 389125813949115973, 39853422352958799040, 4433527105413108692851, 532370587431255626482816
OFFSET
0,3
FORMULA
E.g.f.: A(x) = (1/x)*Series_Reversion(x/C(x)) where C(x) is the e.g.f. of A141357.
E.g.f.: A(x) = x/Series_Reversion(x*D(x)) where D(x) is the e.g.f. of A141359.
E.g.f.: A(x) = B(x*A(x)^2) where B(x) = exp(x*B(x)*exp(x^2*B(x)^2*exp(x^3*B(x)^3*exp(...)))) is the e.g.f. of A141356 = [1,1,3,22,245,3516,63727,1405384,...].
E.g.f.: A(x) = C(x*A(x)) where C(x) = exp(x*C(x)^2*exp(x^2*C(x)^4*exp(x^3*C(x)^6*exp(...)))) is the e.g.f. of A141357 = [1,1,5,55,945,21961,645013,22948815,...].
E.g.f.: A(x) = D(x/A(x)) where D(x) = exp(x*D(x)^4*exp(x^2*D(x)^8*exp(x^3*D(x)^12*exp(...)))) is the e.g.f. of A141359 = [1,1,9,175,5321,221001,11659345,746678311,...].
EXAMPLE
E.g.f.: A(x) = 1 + x + 7*x^2/2! + 106*x^3/3! + 2509*x^4/4! + 80956*x^5/5! +...
PROG
(PARI) {a(n)=local(A=1+x, F); for(i=0, n, for(j=0, n, F=exp((x*(A+x*O(x^n))^3)^(n-j+1)*F)); A=F); n!*polcoeff(A, n)}
CROSSREFS
Cf. A141356, A141357, A141359; variant: A141362.
Sequence in context: A203971 A145167 A367166 * A141362 A213863 A231899
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jun 28 2008
STATUS
approved