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A106125 Numbers k such that k divides the k-th semiprime. 0
1, 2, 3, 7, 11, 43, 53, 613367, 613439, 613451, 613523, 613549, 613609, 6384425461, 6384425521, 6384425569, 6384425647 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Note that except 1, all other term in the sequence will be primes.

a(18) > 10^12. - Lucas A. Brown, Oct 17 2020

LINKS

Table of n, a(n) for n=1..17.

EXAMPLE

a(4)=7 is a term because 7 divides the 7th semiprime (i.e., 21).

CROSSREFS

Cf. A001358.

Sequence in context: A056354 A072534 A056292 * A175171 A073609 A267091

Adjacent sequences:  A106122 A106123 A106124 * A106126 A106127 A106128

KEYWORD

nonn,more

AUTHOR

Shyam Sunder Gupta, May 07 2005

EXTENSIONS

a(14)-a(17) from Donovan Johnson, Sep 27 2010

STATUS

approved

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Last modified October 26 14:28 EDT 2021. Contains 348267 sequences. (Running on oeis4.)