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A104179 Primes that are either single-digit primes or a concatenation of two earlier terms. 1
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 (list; graph; refs; listen; history; internal format)
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 (jeanmarcfalcoz(at)vtxnet.ch), Mar 28 2009

PROG

(PARI from Maximilian Hasler) 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)))

CROSSREFS

Sequence in context: A154385 A125525 A019546 * A096148 A124674 A177061

Adjacent sequences:  A104176 A104177 A104178 * A104180 A104181 A104182

KEYWORD

nonn,base

AUTHOR

David W. Wilson (davidwwilson(AT)comcast.net), Mar 27 2009

EXTENSIONS

More terms from Maximilian Hasler (maximilian.hasler(AT)gmail.com), Mar 28 2009

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Last modified February 17 07:41 EST 2012. Contains 205998 sequences.