A168529 Primes n that are concatenation of two 3-digit primes p<q.

101107, 101113, 101149, 101173, 101197, 101281, 101293, 101347, 101359, 101383, 101419, 101449, 101467, 101503, 101599, 101641, 101653, 101701, 101719, 101797, 101839, 101863, 101929, 101977, 103307, 103349, 103409, 103421, 103457, 103577

Offset

1,1

Comments

Or, primes of the form 10^3*p+q, p,q primes, 100<p<q<998.

There are exactly 1407 such primes from 101107 to 971977.

Links

Andrew Howroyd, Table of n, a(n) for n = 1..1407 (complete sequence)

Mathematica

p3=Select[Range[100, 999], PrimeQ]; Le=Length@p3; Reap[Do[p=10^3*p3[[i]]; Do[If[PrimeQ[n=p+p3[[k]]], Sow[n]], {k, i+1, Le}], {i, Le-1}]][[2, 1]];

Prog

(PARI) concat(apply(p->select(n->isprime(n) && isprime(n%1000), [1000*p+p+1..1000*p+997]), select(isprime, [101..996]))) \\ Andrew Howroyd, Feb 22 2018

Crossrefs

Subsequence of A105184.

Sequence in context: A068445 A210888 A115828 * A255976 A161796 A096929

Adjacent sequences: A168526 A168527 A168528 * A168530 A168531 A168532

Keyword

base,fini,full,nonn

Author

Zak Seidov, Nov 28 2009

Extensions

Terms a(25) and beyond in b-file corrected by Andrew Howroyd, Feb 22 2018

Status

approved