Re^2: Error-finding program

[Richard Mathar]

njas> From seqfan-owner at ext.jussieu.fr  Thu Oct 26 15:12:03 2006
njas> Date: Thu, 26 Oct 2006 09:10:14 -0400 (EDT)
njas> From: "N. J. A. Sloane" <njas at research.att.com>
njas> To: seqfan at ext.jussieu.fr, franktaw at netscape.net,
njas>         zak seidov <zakseidov at yahoo.com>
njas> Subject: Re: Error-finding program
njas> > > 4561.  14561 is at  least a twin prime. 
njas> > ............
njas> > 
njas> > Me: Yes, it should be 14561,
njas> > and all other terms in A088460 are OK.
njas> > 
njas> > Zak
njas> 
njas> But look: this sequence has keyword "uned"
njas> 
njas> When you see that, it usually means I could
njas> not understand the definition, or that the definition
njas> is not clear.
njas> ...

A008460(n)= A001359(A001359(n))
(ie, one-fold repeated application of A001359)
at least according to the PARI program.

Or "Smaller component of a twin-prime pair which is listed at an OEIS position/index
which is also a smaller component of a twin-prime pair"
.... that is about as far as my English would cary...

Actually the offset of this here, A008460, is 1 if one adopts the
formula above, whereas the offset *after* the first application of A001359 would
be 3. The offset is not really well defined so far.

Examples
n=1 -> A001359(1)=3  -> A001359(3)=11 = A0088460(offset)
n=2 -> A001359(2)=5  -> A001359(5)=29  = A0088460(offset+1)
n=3 -> A001359(3)=11  -> A001359(11)=137 = A0088460(offset+2)

Richard