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A178899 Numbers which are both primes and problimes (third definition). 1
2, 7, 11, 19, 23, 43, 53, 73, 79, 97, 103, 109, 127, 139, 151, 157, 163, 181, 193, 199, 211, 1873, 1999, 2017, 2053, 2089, 2143, 2161, 2179, 2251, 2269, 2287, 2341, 2377, 2467, 2503, 2521, 2539, 2557, 2593, 2647, 2683, 2719, 2791, 2917, 2953, 2971, 3061, 3079 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..1000

FORMULA

A000040 INTERSECTION A003068.

MAPLE

b:= proc(n) option remember; local k;

      if n=1 then c(2):= 1; 2

             else k:= ceil (b(n-1) +1/mul((1-1/b(j)), j=1..n-1));

                  c(k):= n; k

      fi

    end:

a:= proc(n) option remember; local k;

      if n=1 then b(1)

             else for k from c(a(n-1))+1 while not isprime (b(k))

                  do od; b(k)

      fi

    end:

seq (a(n), n=1..50);  # Alois P. Heinz, Dec 29 2010

CROSSREFS

Cf. A000040, A003068, A178532.

Sequence in context: A166862 A105881 A060191 * A023393 A084619 A236478

Adjacent sequences:  A178896 A178897 A178898 * A178900 A178901 A178902

KEYWORD

nonn

AUTHOR

Jonathan Vos Post, Dec 29 2010

EXTENSIONS

More terms from Alois P. Heinz, Dec 29 2010

STATUS

approved

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Last modified September 17 22:53 EDT 2019. Contains 327147 sequences. (Running on oeis4.)