A104179 Primes that are either single-digit primes or a concatenation of two earlier terms.

2, 3, 5, 7, 23, 37, 53, 73, 223, 233, 337, 353, 373, 523, 733, 773, 2237, 2333, 3373, 3533, 3733, 5233, 5237, 5323, 7333, 7523, 23333, 23773, 25237, 32237, 33533, 33773, 35323, 35353, 37223, 37337, 52237, 53233, 53353, 53773, 73523, 75323, 77323

Offset

1,1

Links

Jean-Marc Falcoz, Table of n, a(n) for n = 1..1003

Formula

Up to 10^12 there are only 1003 terms and the n-th term seems to be roughly n^(10/e). - Jean-Marc Falcoz, Mar 28 2009

Prog

(PARI) isDW(p, i=1)={while(p>i*=10, setminus(Set(divrem(p, i)), a)|return(eval(Set(Vec(Str(p)))[1]))); p<9}
a=[]; forprime( p=2, 99999, isDW(p) & !print1(p", ") & a=setunion(a, Set(p))) \\ M. F. Hasler, Mar 28 2009

Crossrefs

Sequence in context: A154385 A125525 A019546 * A096148 A211681 A124674

Adjacent sequences: A104176 A104177 A104178 * A104180 A104181 A104182

Keyword

nonn,base

Author

David W. Wilson, Mar 27 2009

Extensions

More terms from M. F. Hasler, Mar 28 2009

Status

approved