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A116025 sigma(n) plus n gives a semiprime (A001358). 1
7, 9, 14, 15, 17, 18, 19, 20, 22, 32, 39, 43, 45, 46, 47, 49, 50, 51, 59, 61, 62, 68, 70, 71, 72, 79, 81, 86, 91, 93, 95, 101, 104, 107, 109, 110, 115, 116, 117, 118, 121, 123, 129, 130, 142, 149, 151, 158, 160, 163, 164, 165, 167, 177, 185, 187, 197, 201, 207 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

sigma(101)+101=203=7*29.

MATHEMATICA

Select[Range[300], PrimeOmega[DivisorSigma[1, #]+#]==2&] (* Harvey P. Dale, May 21 2014 *)

CROSSREFS

Cf. A001358, A116014.

Sequence in context: A063189 A004472 A145827 * A344011 A320325 A320699

Adjacent sequences:  A116022 A116023 A116024 * A116026 A116027 A116028

KEYWORD

nonn

AUTHOR

Giovanni Resta, Feb 13 2006

STATUS

approved

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Last modified December 5 12:24 EST 2021. Contains 349557 sequences. (Running on oeis4.)