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 A083904 G.f. 1/(1-x) * sum(k>=0, 3^k*x^2^(k+1)/(1+x^2^k)). 0
 0, 1, 0, 4, 3, 1, 0, 13, 12, 10, 9, 4, 3, 1, 0, 40, 39, 37, 36, 31, 30, 28, 27, 13, 12, 10, 9, 4, 3, 1, 0, 121, 120, 118, 117, 112, 111, 109, 108, 94, 93, 91, 90, 85, 84, 82, 81, 40, 39, 37, 36, 31, 30, 28, 27, 13, 12, 10, 9, 4, 3, 1, 0, 364, 363, 361, 360 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS Distance to next number of form 2^k-1, written down in binary, then interpreted as ternary. Thus the numbers have no 2 in ternary representation. LINKS Ralf Stephan, Table of generating functions FORMULA a(1)=0, a(2n) = 3a(n)+1, a(2n+1) = 3a(n). a(n) = 1/2*(3^(floor(log2(n))+1)-1) - A005836(n). PROG (PARI) for(n=1, 100, l=ceil(log(n)/log(2)); t=polcoeff(1/(1-x)*sum(k=0, l, 3^k*(x^2^(k+1))/(1+x^2^k)) + O(x^(n+1)), n); print1(t", ")) CROSSREFS Cf. A005823, A005836. Sequence in context: A136590 A117026 A316656 * A215861 A195596 A129810 Adjacent sequences:  A083901 A083902 A083903 * A083905 A083906 A083907 KEYWORD nonn,easy AUTHOR Ralf Stephan, Jun 18 2003 STATUS approved

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Last modified April 24 10:11 EDT 2019. Contains 322420 sequences. (Running on oeis4.)