A229814 - OEIS

A229814

Primes which are a concatenation of prime(i) and prime(prime(i)) for some i.

23, 1759, 2383, 41179, 61283, 71353, 83431, 127709, 2271433, 3372269, 3532381, 4993559, 5033593, 5714153, 7275503, 8876899, 9117109, 9377351, 9717649, 10618513, 142711909, 157913297, 166314107, 169314437, 170914591, 187116073, 187716127, 190716451, 194916901

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OFFSET

1,1

LINKS

K. D. Bajpai, Table of n, a(n) for n = 1..10000

EXAMPLE

a(2)=1759: prime(7)= 17 and prime(17)= 59. Concatenating 17 and 59 gives 1759 which is prime.

a(4)=41179: prime(13)= 41 and prime(41)= 179. Concatenating 41 and 179 gives 41179 which is prime.

MAPLE

K := proc(n) local a, b, d; a :=ithprime(n); b:=ithprime(a); d:=parse(cat(a, b)); if isprime(d) then return (d) end if; end proc:

seq(K(n), n=1..1000);

CROSSREFS