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 A072612 Minimal value of { abs(n-sigma(k)) : k>0 }. 0
 0, 1, 0, 0, 1, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 1, 1, 0, 1, 0, 1, 2, 1, 0, 1, 2, 1, 0, 1, 0, 0, 0, 1, 2, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 2, 1, 0, 1, 2, 3, 2, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 2, 3, 1, 0, 1, 2, 1, 0, 1, 0, 1, 2, 1, 0, 1, 0, 1, 2, 1, 0, 1, 2, 3, 2, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 2, 1, 0, 1, 0, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,10 COMMENTS a(A002191(k)) = 0 LINKS FORMULA Conjecture : S(n) = sum( k=1, n, a(k) ) = n + O(sqrt(n)) and more precisely for n large enough : n - (5/2)*sqrt(n) < S(n) < n - (3/2)*sqrt(n) PROG (PARI) a(n)=vecmin(vector(n, k, abs(n-sigma(k)))) CROSSREFS Sequence in context: A049816 A328958 A143542 * A116378 A321854 A227839 Adjacent sequences:  A072609 A072610 A072611 * A072613 A072614 A072615 KEYWORD easy,nonn AUTHOR Benoit Cloitre, Aug 11 2002 STATUS approved

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Last modified August 5 03:00 EDT 2021. Contains 346457 sequences. (Running on oeis4.)