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A097223
Prime numbers p such that p = prime(n) and n = product of the digits of p.
10
17, 73, 2475989
OFFSET
1,1
COMMENTS
This sequence is a subsequence of A097220, so the sequence is also a subsequence of A097221. Next term if it exists is greater than 4333000000.
There is no further term. [Farideh Firoozbakht, Jul 15 2009]
LINKS
Chris K. Caldwell and G. L. Honaker, Jr., 2475989
Carl Pomerance, What we still don't know about addition and multiplication, Trjitzinsky Lecture 1, U. Illinois Urbana-Champaign, November 27, 2018. See slides 22 & 24.
EXAMPLE
2475989 is in the sequence because 2475989 is (2*4*7*5*9*8*9)-th prime.
MATHEMATICA
v={}; Do[If[h=IntegerDigits[Prime[n]]; l=Length[h]; p=Product[h[[k]], {k, l}]; p==n, v=Append[v, Prime[n]]; Print[v]], {n, 205000000}]
PROG
(PARI) isok(p) = isprime(p) && (primepi(p) == vecprod(digits(p))); \\ Michel Marcus, Jan 27 2019
CROSSREFS
Sequence in context: A165691 A154419 A208399 * A296113 A231779 A063494
KEYWORD
base,fini,full,nonn,bref
AUTHOR
Farideh Firoozbakht, Aug 06 2004
STATUS
approved