[seqfan] Re: Primes embedded

[zak seidov]

Here you are:

http://zak08.livejournal.com/21051.html
First 1000 terms of A169798

Zak

--- On Sat, 5/15/10, N. J. A. Sloane <njas at research.att.com> wrote:

> From: N. J. A. Sloane <njas at research.att.com>
> Subject: [seqfan] Re: Primes embedded
> To: seqfan at list.seqfan.eu
> Cc: njas at research.att.com
> Date: Saturday, May 15, 2010, 11:55 PM
> Eric Angelini suggested this two
> weeks ago, but I have
> only now had a chance to study it:
> 
> a(n) > a(n-1) and a(n) is the smallest available
> composite
> embedding the smallest not yet embedded prime:
>  
> S=12,30,35,57,110,130,170,190,230,290,310,370,410,430,447,451,...
> p= 2 3   5  7 11  13 
> 17  19  23  29  31  37 
> 41  43   47  51 ...
> 
> 
> I see that it met with vigorous opposition.
> 
> But allow me to defend it!  I have spent the past 11
> hours
> processing submissions and edits and emails about
> sequences,
> and it is pretty tough going.   Almost every
> sequence I looked at
> needed work, and I looked at a LOT of sequences today.
> It was a a pretty humorless day.
> 
> On the other hand, this one made me laugh.  So in
> spite of
> the objections, I am not only going to add it, I'm also
> adding a mate to it:
> 
> %I A144565
> %S A144565
> 12,30,35,57,110,130,170,190,230,290,310,370,410,430,447,451
> %N A144565 a(n) = smallest composite number > a(n-1)
> that contains the n-th prime as a substring.
> %O A144565 1,1
> %K A144565 nonn,base,more
> %Y A144565 Cf. A169798.
> %e A144565 S =
> 12,30,35,57,110,130,170,190,230,290,310,370,410,430,447,451,...
> %e A144565 p =
> .2.3...5..7.11..13..17..19..23..29..31..37..41..43...47..51....
> %A A144565 Eric Angelini, May 01 2010
> 
> %I A169798
> %S A169798 41,61,83,89,101,127,149,151,163,181,2003,2111
> %N A169798 a(n) = smallest prime number > a(n-1) that
> contains the n-th composite number as a substring.
> %O A169798 1,1
> %K A169798 nonn,base,more
> %Y A169798 Cf. A144565.
> %A A169798 N. J. A. Sloane (njas(AT)research.att.com), May
> 15 2010
> 
> Besides, these could easily appear on some IQ test one
> day.
> 
> Neil
> 
> 
> 
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