O.g.f.: A(x) = 1 + x + 130561*x^2 + 1268169652561*x^3 + 196425341268811084961*x^4 + 236460748444613412476233431261*x^5 + ...
ILLUSTRATION OF DEFINITION.
The table of coefficients of x^k/k! in exp(n^9*x)/A(x) begins
n = 1: [1, 0, -261121, -7609017132002, ...];
n = 2: [1, 511, 0, -7609283997664, ...];
n = 3: [1, 19682, 387120003, 0, ...];
n = 4: [1, 262143, 68718691328, 18006377981579296, 0, ...];
n = 5: [1, 1953124, 3814693098255, 7450560013815682610, 14547105795912570137404925, 0, ...];
...
in which a diagonal, the coefficient of x^n in row n, is all zeros.