OFFSET
1,2
REFERENCES
Serge Francinou, Herve Gianella and Serge Nicolas, Exercices de mathématiques : oraux X-ENS, Analyse 1, Cassini Editeur, 2003, pp. 119-121.
FORMULA
a(n) = r*n + o(n) where r is the solution to x + log(x) = 0 and 0 < x < 1: r = 0.56714329040978387299996... (see A030178).
PROG
(PARI) a(n)=if(n<0, 0, k=1; while(sum(i=0, 2*n-1, (-k)^i*1./i!)>0, k++); k)
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Jun 08 2008
STATUS
approved