login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A084669 Primes which are a concatenation of prime(n) and n. 8

%I

%S 53,239,6719,7321,15737,30763,38977,41981,44987,587107,661121,751133,

%T 1051177,1229201,1297211,1303213,1327217,1823281,1913293,1999303,

%U 2131321,2179327,2207329,2239333,2371351,2689391,2699393,3067439

%N Primes which are a concatenation of prime(n) and n.

%e a(2)=239 because prime[9]=23 and concatenation of 23 and 9 is 239 which is prime.

%t Select[Table[FromDigits[Flatten[{IntegerDigits[Prime[n]], IntegerDigits[n]}]], {n, 1, 500}], PrimeQ]

%o (MAGMA) [p: n in [1..500] | IsPrime(p) where p is Seqint(Intseq(n) cat Intseq(NthPrime(n)))]; // _Bruno Berselli_, Sep 15 2015

%Y Cf. A084667.

%Y Subsequence of primes of A075110.

%K nonn,base

%O 1,1

%A _Zak Seidov_, Jun 29 2003

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 26 10:17 EDT 2022. Contains 354086 sequences. (Running on oeis4.)