primes in arithmetic progression
Jonathan Post
jvospost3 at gmail.com
Sat Nov 4 19:37:19 CET 2006
Sorry, I mean: "The semiprime analogue of this is a table that shows the
smallest semiprime S of k (not necessarily consecutive) SEMIprimes in
arithmetic progression
with common difference d."
On 11/4/06, Jonathan Post <jvospost3 at gmail.com> wrote:
>
> The semiprime analogue of this is a table that shows the smallest
> semiprime S
> of k (not necessarily consecutive) primes in arithmetic progression
> with common difference d (once a 0 appears, the row has ended nonzero
> values):
>
> d k+1 k=2 k=3 k=4 k=5 k=6 k=7 k=8
> 0 4 4 4 4 4 4 4 ...
> 1 4 9 33 0
> 2 4 4 91 213 1383 8129 3091 0
> 3 4 6 115
> 4 4 6 6 111
> 5 4 4 77
> 6 4 4
> 7 4 14 51
> 8 4 6 6 69
>
> -- Fairly easy to extend, fairly easy to prove the first 0 in a row.
>
> The same can be done for 3-almost primes, 4-almost primes, and so forth,
> this making a 3-dimensional array.
>
>
>
> On 11/4/06, Richard Mathar <mathar at strw.leidenuniv.nl> wrote:
> >
> >
> > Is there an OEIS table that shows the smallest prime p
> > of k (not necessarily consecutive) primes in arithmetic progression
> > with common difference d? The table would look similar to this one
> > below, and contain rather large primes where I am leaving blanks:
> >
> > k=1 k=2 k=3 k=4 k=5 k=6
> > d
> > 0 2 2 2 2 2 2
> > 2 2 3 3
> > 4 2 3 3
> > 6 2 5 5 5 5
> > 8 2 3 3
> > 10 2 3 3
> > 12 2 5 5 5 5
> > 14 2 3 3
> > 16 2 3
> > 18 2 5 5 5
> > 20 2 3
> > 22 2 7
> > 24 2 5 5 59
> > 26 2 3
> > 28 2 3 3
> > 30 2 7 7 7 7 7
> > 32 2 5
> > 34 2 3 3
> > 36 2 5 7 31
> >
> > The row d=0 and the column k=1 are degenerate and filled with the
> > prime 2. All strides d are even. Example for row d=24 and column k=4:
> > The 4 numbers 59,59+24,59+2*24 and 59+3*24 are all primes.
> >
> > http://www.research.att.com/~njas/sequences/Sindx_Pri.html#primes_AP<http://www.research.att.com/%7Enjas/sequences/Sindx_Pri.html#primes_AP>
> >
> > --Richard
> >
>
>
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