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

Offset: 1

Author

K. D. Bajpai, Sep 30 2013

Keywords

• nonn
• base
• less

Examples

			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.
		

Links

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

Crossrefs

Cf. A030459, A045533.

Programs

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);