A059118 Composite solutions to sigma(x)+8 = sigma(x+8).

27, 1615, 1885, 218984, 4218475, 312016315, 746314601, 1125845307, 1132343549, 1296114929, 9016730984, 303419868239, 1197056419121, 2065971192041, 2948269852109, 4562970154601

Offset: 1

Author

Jud McCranie, Jan 06 2001

Keywords

• nonn
• more

Comments

a(17) > 10^13. - Giovanni Resta, Jul 11 2013

Examples

			sigma(27)+8 = 48 = sigma(27+8), so 27 is in the sequence.
		

References

• The first 4 terms were found by Labos Elemer, see A015915.

Crossrefs

Cf. A015915.

Programs

Mathematica

ta={{0}};Do[If[Equal[DivisorSigma[1, n+8] -DivisorSigma[1, n]-8, 0]&&!PrimeQ[n], Print[n]; ta=Append[ta, n]], {n, 1000000000, 1300000000}]; ta=Delete[ta, 1] (* Labos Elemer, Jan 10 2005 *)

Extensions

a(8)-a(10) terms from Labos Elemer, Jan 10 2005

Offset corrected and a(11) added by Donovan Johnson, Dec 07 2008

a(12)-a(16) from Giovanni Resta, Jul 11 2013