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A250295 Numbers n such that A005165(n) is a semiprime. 0
9, 11, 12, 17, 18, 23, 26, 31, 62, 64, 67, 76, 78, 84, 87, 88, 123, 125, 131 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(20) >= 150. - Max Alekseyev, Aug 26 2021

LINKS

Table of n, a(n) for n=1..19.

Hisanori Mishima, Factorizations of many number sequences

Hisanori Mishima, Factorizations of many number sequences

EXAMPLE

a(1) = 9 so A005165(9) = 326981 = 79 * 4139 is a semiprime.

CROSSREFS

Cf. A001272, A005165.

Sequence in context: A202707 A031078 A216292 * A071217 A064930 A158607

Adjacent sequences:  A250292 A250293 A250294 * A250296 A250297 A250298

KEYWORD

nonn

AUTHOR

Eric Chen, Dec 24 2014

EXTENSIONS

a(18)-a(19) from Max Alekseyev, Aug 26 2021

STATUS

approved

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Last modified January 17 22:33 EST 2022. Contains 350410 sequences. (Running on oeis4.)