OFFSET
0,9
COMMENTS
The number of contiguous signs appear to increase (roughly) in proportion to the square-root of the number of terms.
LINKS
Paul D. Hanna, Table of n, a(n) for n = 0..1000
EXAMPLE
G.f.: A(x) = 1 - x^4 - x^6 - 3*x^8 - x^9 - 4*x^12 + x^13 + 3*x^14 + 4*x^16 +...
where
log(A(x)) = -4*x^4/4 - 6*x^6/6 - 28*x^8/8 - 9*x^9/9 - 10*x^10/10 - 94*x^12/12 - 14*x^14/14 - 15*x^15/15 - 140*x^16/16 +...
PROG
(PARI) {a(n)=polcoeff(exp(sum(m=1, n, (sigma(m^2)-sigma(m)^2/2-sigma(m, 2)/2)*x^m/m)+x*O(x^n)), n)}
for(n=0, 70, print1(a(n), ", "))
CROSSREFS
KEYWORD
sign
AUTHOR
Paul D. Hanna, Sep 30 2012
STATUS
approved