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 A062087 Squarefree numbers with all prime digits. 0
 2, 3, 5, 7, 22, 23, 33, 35, 37, 53, 55, 57, 73, 77, 222, 223, 227, 233, 235, 237, 253, 255, 257, 273, 277, 322, 323, 327, 335, 337, 353, 355, 357, 373, 377, 523, 527, 533, 535, 537, 553, 555, 557, 573, 577, 723, 727, 733, 737, 753, 755, 757, 773, 777, 2222, 2227 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Heuristically, there are about 4^n * 275/(48*Pi^2) n-digit members of this sequence. [Charles R Greathouse IV, Oct 18 2011] LINKS EXAMPLE a(6)= 23, 2 and 3 are both primes. MATHEMATICA Select[Range[3000], Abs[MoebiusMu[#]] == 1 && Union[PrimeQ[IntegerDigits[#]]] == {True} &] (* Alonso del Arte, Oct 18 2011 *) CROSSREFS Sequence in context: A085557 A125665 A046034 * A162457 A084983 A062239 Adjacent sequences:  A062084 A062085 A062086 * A062088 A062089 A062090 KEYWORD nonn,base AUTHOR Amarnath Murthy, Jun 16 2001 EXTENSIONS Corrected and extended by Larry Reeves (larryr(AT)acm.org), Jun 18 2001 Offset corrected by Arkadiusz Wesolowski, Oct 18 2011 STATUS approved

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Last modified December 5 06:51 EST 2020. Contains 338944 sequences. (Running on oeis4.)