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 A167439 Length of the longest partition of n into distinct parts, with each part divisible by the next one. 4
 0, 1, 1, 2, 2, 2, 2, 3, 2, 3, 3, 3, 2, 3, 3, 4, 3, 3, 3, 4, 3, 4, 4, 4, 2, 3, 3, 4, 4, 4, 4, 5, 3, 4, 4, 4, 4, 4, 4, 5, 4, 4, 4, 5, 4, 5, 5, 5, 3, 4, 4, 4, 4, 4, 4, 5, 4, 5, 5, 5, 4, 5, 5, 6, 5, 4, 4, 5, 4, 5, 5, 5, 4, 5, 4, 5, 5, 5, 5, 6, 4, 5, 5, 5, 4, 5, 5, 6, 5, 5, 5, 6, 5, 6, 6, 6, 5, 4, 4, 5, 5, 5, 4, 5, 4 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS a(n) > sqrt(log(n))/2. REFERENCES V. A. Sadovnichiy, A. A. Grigoryan and S. V. Konyagin (1987), "Problems of mathematical olympiads for university students". Section 4.1, problem 25. (in Russian) LINKS FORMULA a(n) = max{ A167866(n), A167866(n-1) + 1 }. PROG (PARI) { a(n, m=0) = local(r=0); if(n==0, return(0)); fordiv(n, d, if(d<=m, next); r=max(r, 1+a((n-d)\d, 1)) ); r } CROSSREFS Cf. A122651, A167439, A167865, A167866. Sequence in context: A068211 A236832 A089050 * A272314 A241216 A125173 Adjacent sequences:  A167436 A167437 A167438 * A167440 A167441 A167442 KEYWORD nonn AUTHOR Max Alekseyev, Nov 13 2009, Nov 15 2009 STATUS approved

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Last modified April 1 02:15 EDT 2020. Contains 333153 sequences. (Running on oeis4.)