A300616 E.g.f. A(x) satisfies: [x^n] A(x)^n = n^2 * [x^(n-1)] A(x)^n for n>=1.

1, 1, 7, 199, 14065, 1924201, 445859911, 161145717727, 85790577700129, 64427620614173425, 65943035132156264071, 89425725156530626400791, 156922032757769223085752337, 349233620942232034199096926489, 968890106809715834110637461124935, 3301188169350221687517822373590448111, 13634136452997022097853039839798901714241

Offset

0,3

Comments

Compare e.g.f. to: [x^n] exp(x)^n = [x^(n-1)] exp(x)^n for n>=1.

Compare to e.g.f. G(x) of A182962: [x^n] G(x)^n = n * [x^(n-1)] G(x)^n for n>=1.

Links

Paul D. Hanna, Table of n, a(n) for n = 0..300

Formula

E.g.f. A(x) satisfies: log(A(x)) = Sum_{n>=1} A300617(n)*x^n, a power series in x with integer coefficients.

a(n) ~ c * (n!)^3, where c = 1.685041722777551007711429045295022018562828... - Vaclav Kotesovec, Mar 10 2018

Example

E.g.f.: A(x) = 1 + x + 7*x^2/2! + 199*x^3/3! + 14065*x^4/4! + 1924201*x^5/5! + 445859911*x^6/6! + 161145717727*x^7/7! + 85790577700129*x^8/8! + ...
ILLUSTRATION OF DEFINITION.
The table of coefficients of x^n in A(x)^n begins:
n=1: [(1), (1), 7/2, 199/6, 14065/24, 1924201/120, 445859911/720, ...];
n=2: [1, (2), (8), 220/3, 3752/3, 502114/15, 57409744/45, ...];
n=3: [1, 3, (27/2), (243/2), 16035/8, 2098161/40, 157765131/80, ...];
n=4: [1, 4, 20, (536/3), (8576/3), 1096868/15, 121987336/45, ...];
n=5: [1, 5, 55/2, 1475/6, (91825/24), (2295625/24), 503279435/144, ...];
n=6: [1, 6, 36, 324, 4920, (601074/5), (21638664/5), 7491519768/35...];
n=7: [1, 7, 91/2, 2485/6, 147721/24, 17641687/120, (3752979139/720), (183895977811/720), ...]; ...
in which the coefficients in parenthesis are related by
1 = 1*1; 8 = 2^2*2; 243/2 = 3^2*27/2; 8576/3 = 4^2*536/3; ...
illustrating that: [x^n] A(x)^n = n^2 * [x^(n-1)] A(x)^n.
LOGARITHMIC PROPERTY.
The logarithm of the e.g.f. is the integer series:
log(A(x)) = x + 3*x^2 + 30*x^3 + 550*x^4 + 15375*x^5 + 601398*x^6 + 31299268*x^7 + 2093655600*x^8 + 175312873125*x^9 + 17987972309725*x^10 + ... + A300617(n)*x^n + ...

Prog

(PARI) {a(n) = my(A=[1]); for(i=1, n+1, A=concat(A, 0); V=Vec(Ser(A)^(#A-1)); A[#A] = ((#A-1)^2*V[#A-1] - V[#A])/(#A-1) ); n!*A[n+1]}
for(n=0, 20, print1(a(n), ", "))

Crossrefs

Cf. A182962, A296170, A300590, A300592, A300594, A300596, A300614, A300617.

Sequence in context: A068233 A154936 A206473 * A370084 A178319 A202943

Adjacent sequences: A300613 A300614 A300615 * A300617 A300618 A300619

Keyword

nonn

Author

Paul D. Hanna, Mar 10 2018

Status

approved