[seqfan] Re: A119911

[Moses, Peter J. C.]

Hi Harvey,

I find that this:

LucasQ[n_]:=IntegerQ[Sqrt[5 n^2+20]]||IntegerQ[Sqrt[5 n^2-20]]
Select[Range[102],!LucasQ[DivisorSigma[0,#]]&]

gives the same numbers as A119911.

To make yours give the same numbers, make lnos=LucasL[Range[0,20]].  This 
will then include 2 as a Lucas number.

Best regards,
Peter.


Peter. J. C. Moses.
Moparmatic Co.
1154 Evesham Road.
Astwood Bank.
Redditch.
Worcs.
B96 6DT.
England.
Tel & Fax: +44 1527 892413.
52°15.713' N. 001°56.256' W

-----Original Message----- 
From: Harvey P. Dale
Sent: Sunday, May 11, 2014 2:23 PM
To: Sequence Fanatics Discussion list
Subject: [seqfan] A119911

Are the terms of this sequence correct?  The sequence lists only 38 terms 
less than 103, whereas I get 64 such terms.
Here is the Mma program I used: 
With[{lnos=LucasL[Range[20]]},Select[Range[300],!MemberQ[lnos,DivisorSigma[0,#]]&]]
Best,
Harvey


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