A116025 sigma(n) plus n gives a semiprime (A001358).

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

Offset: 1

Author

Giovanni Resta, Feb 13 2006

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Cf. A001358, A116014.

Programs

Mathematica

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