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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

Table of n, a(n) for n=1..105.

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.)