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 A347244 Characteristic function of A347242. 7
 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1 LINKS FORMULA a(1) = 0, and for n > 1, a(n) = 1 if for some k > 0, A006530(A000593^(k)(n)) >= A006530(n), otherwise 0. Here A000593^(k) means the k-fold application of the sum of odd divisors. For n >= 1, a(n) = 0 iff A347245(n) = 0. PROG (PARI) A000265(n) = (n >> valuation(n, 2)); A000593(n) = sigma(A000265(n)); A006530(n) = if(1==n, n, my(f=factor(n)); f[#f~, 1]); A347244(n) = { my(gpf=A006530(n)); while(n>1, n = A000593(n); if(A006530(n)>=gpf, return(1))); (0); }; CROSSREFS Cf. A000593, A006530, A347240, A347242, A347243, A347245, A347246. Sequence in context: A037816 A297038 A044939 * A037824 A025461 A169674 Adjacent sequences:  A347241 A347242 A347243 * A347245 A347246 A347247 KEYWORD nonn AUTHOR Antti Karttunen, Aug 28 2021 STATUS approved

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Last modified January 29 00:42 EST 2022. Contains 350670 sequences. (Running on oeis4.)