A106222 Coefficients of g.f. A(x) where 0 <= a(n) <= 4 for all n>1, with initial terms {1,5}, such that A(x)^(1/5) consists entirely of integer coefficients.

1, 5, 0, 0, 0, 1, 0, 0, 0, 0, 3, 0, 0, 0, 0, 1, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 3, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4, 0, 0, 0, 0, 2, 0, 0, 0, 0, 3, 0, 0, 0, 0, 3, 0, 0, 0, 0, 3, 0, 0, 0, 0, 4, 0, 0, 0, 0, 1, 0, 0, 0, 0, 3, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 4, 0, 0, 0, 0

Offset

0,2

Comments

Equals the self-convolution 5th power of A106223. What is the frequency of occurrence of the nonzero digits?

Links

Table of n, a(n) for n=0..104.

Formula

A(z)=0 at z=-0.1999361633111821182995648612577212067...

Example

A(x) = 1 + 5*x + x^5 + 3*x^10 + x^15 + 4*x^20 + x^35 +...
A(x)^(1/5) = 1 + x - 2*x^2 + 6*x^3 - 21*x^4 + 80*x^5 - 320*x^6 +-...
A106223 = {1,1,-2,6,-21,80,-320,1326,-5637,24434,...}.

Prog

(PARI) {a(n)=local(A=1+5*x); if(n==0, 1, for(j=1, n, for(k=0, 4, t=polcoeff((A+k*x^j+x*O(x^j))^(1/5), j); if(denominator(t)==1, A=A+k*x^j; break))); return(polcoeff(A+x*O(x^n), n)))}

Crossrefs

Cf. A106223, A106216, A106220, A106224, A106226.

Sequence in context: A228631 A101194 A196344 * A368864 A368863 A090750

Adjacent sequences: A106219 A106220 A106221 * A106223 A106224 A106225

Keyword

nonn

Author

Paul D. Hanna, May 01 2005

Status

approved