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 A317441 a(n) = number of k with 1 <= k <= n-1 such that a(k) and a(n-k) have the same binary length (A070939). 2
 0, 1, 2, 1, 2, 3, 0, 5, 4, 1, 6, 3, 0, 5, 4, 1, 10, 5, 2, 7, 0, 7, 10, 5, 6, 7, 2, 5, 8, 5, 8, 7, 10, 9, 6, 7, 8, 7, 10, 11, 6, 7, 8, 11, 6, 17, 8, 9, 8, 19, 8, 13, 10, 15, 6, 19, 10, 9, 6, 19, 8, 13, 14, 13, 10, 17, 14, 15, 10, 19, 14, 9, 16, 15, 10, 11, 20 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS See A317420 for similar sequences. LINKS Rémy Sigrist, Table of n, a(n) for n = 1..10000 Rémy Sigrist, Scatterplot of the first 500000 terms EXAMPLE For n = 4: - A070939(a(1)) = 1 <> 2 = A070939(a(3)), - A070939(a(2)) = 1 = 1 = A070939(a(2)), - A070939(a(3)) = 2 <> 1 = A070939(a(1)), - hence a(4) = 1. PROG (PARI) l = vector(77); for (n=1, #l, l[n] = #binary(max(1, v=sum(k=1, n-1, l[k]==l[n-k]))); print1 (v ", ")) CROSSREFS Cf. A070939, A317420. Sequence in context: A082501 A249858 A249857 * A249777 A289065 A132815 Adjacent sequences: A317438 A317439 A317440 * A317442 A317443 A317444 KEYWORD nonn,base AUTHOR Rémy Sigrist, Jul 28 2018 STATUS approved

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Last modified September 14 06:47 EDT 2024. Contains 375918 sequences. (Running on oeis4.)