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A179859 Numbers n that divide the sum of the first n noncomposites. 2
1, 3, 7, 225, 487, 735, 50047, 142835, 170209, 249655, 316585343, 374788043, 2460457827, 2803329305, 6860334657 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A variant of A045345 (primes), A053781 (composites) and A129749 (nonprimes).

LINKS

Table of n, a(n) for n=1..15.

FORMULA

Numbers n such that n | A014284(n).

a(n) = A179861(n) / A179860(n).

a(n+1) = A158682(n) + 1.

EXAMPLE

The sum of the first 7 noncomposites is 42 = 6*7, so 7 is in the sequence.

CROSSREFS

Cf. A008578 (noncomposites), A014284 (sum of first n noncomposites).

Cf. A179860, A179861.

Sequence in context: A291352 A132564 A057619 * A061422 A206333 A088097

Adjacent sequences:  A179856 A179857 A179858 * A179860 A179861 A179862

KEYWORD

nonn,more

AUTHOR

Ray Chandler, Jul 29 2010

STATUS

approved

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Last modified July 19 08:12 EDT 2019. Contains 325155 sequences. (Running on oeis4.)