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 A083661 G.f.: 1/(1-x) * Sum_{k>=0} x^2^(k+2)/(1+x^2^k). 2
 0, 0, 0, 1, 0, 1, 0, 2, 1, 1, 0, 2, 1, 1, 0, 3, 2, 2, 1, 2, 1, 1, 0, 3, 2, 2, 1, 2, 1, 1, 0, 4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0, 4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0, 5, 4, 4, 3, 4, 3, 3, 2, 4, 3, 3, 2, 3, 2, 2, 1, 4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,8 LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 Ralf Stephan, Some divide-and-conquer sequences with (relatively) simple ordinary generating functions, 2004. Ralf Stephan, Table of generating functions. FORMULA a(1) = a(2) = a(3) = 0, a(2n) = a(n)+1, a(2n+1) = a(n). a(n) = A080791(n) + A079944(n-2) - 1. MATHEMATICA a[n_] := DigitCount[n, 2, 0] + IntegerDigits[n, 2][[2]] - 1; a[1] = 0; Array[a, 100] (* Amiram Eldar, Jul 16 2023 *) PROG (PARI) for(n=1, 120, l=ceil(log(n)/log(2)); t=polcoeff(1/(1-x)*sum(k=0, l, (x^2^(k+2))/(1+x^2^k)) + O(x^(n+1)), n); print1(t", ")) CROSSREFS Cf. A000120, A023416, A079944, A080791. Sequence in context: A060826 A078134 A282380 * A029369 A255315 A125072 Adjacent sequences: A083658 A083659 A083660 * A083662 A083663 A083664 KEYWORD nonn,easy AUTHOR Ralf Stephan, Jun 14 2003 STATUS approved

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Last modified October 1 15:27 EDT 2023. Contains 365826 sequences. (Running on oeis4.)