The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A059118

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Showing entries 1-10 | older changes

A059118

Composite solutions to sigma(x)+8 = sigma(x+8).
(history; published version)

#20 by Bruno Berselli at Sun Feb 08 10:30:00 EST 2015

STATUS

proposed

approved

#19 by Michel Marcus at Sun Feb 08 10:12:16 EST 2015

STATUS

editing

proposed

#18 by Michel Marcus at Sun Feb 08 10:12:08 EST 2015

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 *)

STATUS

proposed

editing

#17 by Jon E. Schoenfield at Sun Feb 08 09:15:33 EST 2015

STATUS

editing

proposed

#16 by Jon E. Schoenfield at Sun Feb 08 09:15:29 EST 2015

NAME

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

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_ *)

EXTENSIONS

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

STATUS

approved

editing

#15 by N. J. A. Sloane at Tue Oct 15 22:41:38 EDT 2013

EXTENSIONS

a(8)-a(10) terms from _Labos E.Elemer_(Jan 10 2005);

Discussion

Tue Oct 15

22:41

OEIS Server: https://oeis.org/edit/global/2033

#14 by N. J. A. Sloane at Tue Oct 15 22:30:57 EDT 2013

REFERENCES

The first 4 terms were found by _Labos E. (labos(AT)ana.sote.hu), Elemer_, see A015915.

Discussion

Tue Oct 15

22:30

OEIS Server: https://oeis.org/edit/global/2029

#13 by Bruno Berselli at Thu Jul 11 10:04:07 EDT 2013

STATUS

proposed

approved

#12 by Giovanni Resta at Thu Jul 11 09:55:08 EDT 2013

STATUS

editing

proposed

#11 by Giovanni Resta at Thu Jul 11 09:54:07 EDT 2013

DATA

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

COMMENTS

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

EXTENSIONS

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

STATUS

approved

editing