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 A083905 G.f.: 1/(1-x) * sum(k>=0, (-1)^k*x^2^(k+1)/(1+x^2^k)). 2
 0, 1, 0, 0, -1, 1, 0, 1, 0, 2, 1, 0, -1, 1, 0, 0, -1, 1, 0, -1, -2, 0, -1, 1, 0, 2, 1, 0, -1, 1, 0, 1, 0, 2, 1, 0, -1, 1, 0, 2, 1, 3, 2, 1, 0, 2, 1, 0, -1, 1, 0, -1, -2, 0, -1, 1, 0, 2, 1, 0, -1, 1, 0, 0, -1, 1, 0, -1, -2, 0, -1, 1, 0, 2, 1, 0, -1, 1, 0, -1, -2, 0, -1, -2, -3, -1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,10 COMMENTS For all n, a(3*A006288(n)) = 0 as proved in Russian forum dxdy.ru - see link. LINKS R. Stephan, Some divide-and-conquer sequences ... R. Stephan, Table of generating functions FORMULA a(1)=0, a(2n) = -a(n)+1, a(2n+1) = -a(n). PROG (PARI) for(n=1, 100, l=ceil(log(n)/log(2)); t=polcoeff(1/(1-x)*sum(k=0, l, (-1)^k*(x^2^(k+1))/(1+x^2^k)) + O(x^(n+1)), n); print1(t", ")) CROSSREFS Cf. A065359, A023416. a(n) = A030300(n) - A065359(n). Sequence in context: A300056 A321758 A016102 * A179319 A321916 A257265 Adjacent sequences:  A083902 A083903 A083904 * A083906 A083907 A083908 KEYWORD sign,easy AUTHOR Ralf Stephan, Jun 18 2003 STATUS approved

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Last modified April 25 18:12 EDT 2019. Contains 322461 sequences. (Running on oeis4.)