A089933 Concatenate the first n odd primes.

3, 35, 357, 35711, 3571113, 357111317, 35711131719, 3571113171923, 357111317192329, 35711131719232931, 3571113171923293137, 357111317192329313741, 35711131719232931374143, 3571113171923293137414347, 357111317192329313741434753, 35711131719232931374143475359

Offset: 1

Author

Cino Hilliard, Jan 11 2004

Keywords

• nonn
• base

Comments

Except for a(1) = 3, these numbers are not prime for n < 10000. See A089948.

Links

• Robert Israel, Table of n, a(n) for n = 1..298

Crossrefs

Cf. A019518, A086043, A089948.

Programs

Magma

[Seqint(Reverse(&cat[Reverse(Intseq(NthPrime(k+1))): k in [1..n]])): n in [1..17]]; // Vincenzo Librandi, Nov 30 2015

Maple

a[1]:= 3;
for n from 2 to 100 do
  p:= ithprime(n+1);
  a[n]:= 10^(1+ilog10(p))*a[n-1]+p
od:
seq(a[i],i=1..100); # Robert Israel, Aug 25 2016

Mathematica

Table[FromDigits[Flatten[IntegerDigits[Prime[Range[n] + 1]]]],{n, 20}] (* Vincenzo Librandi, Nov 30 2015 *)

PARI

concatprime(n) = { y=""; forprime(x=3,n, y=concat(Str(y),Str(x)); z=eval(y); print1(z",") ) }

Extensions

Offset changed by Robert Israel, Aug 25 2016