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A077679
Squarefree numbers beginning with 3.
12
3, 30, 31, 33, 34, 35, 37, 38, 39, 301, 302, 303, 305, 307, 309, 310, 311, 313, 314, 317, 318, 319, 321, 322, 323, 326, 327, 329, 330, 331, 334, 335, 337, 339, 341, 345, 346, 347, 349, 353, 354, 355, 357, 358, 359, 362, 365, 366, 367, 370, 371, 373, 374, 377
OFFSET
1,1
COMMENTS
Intersection of A005117 and A217395. - Michel Marcus, Sep 14 2013
Lower density is 1/(5*Pi^2), upper density is 5/(3*Pi^2). - Charles R Greathouse IV, Nov 05 2017
LINKS
MATHEMATICA
Select[Range[400], SquareFreeQ[#]&&IntegerDigits[#][[1]]==3&] (* Harvey P. Dale, Oct 10 2018 *)
PROG
(PARI) isok(n) = (issquarefree(n) && (digits(n, 10)[1] == 3)) \\ Michel Marcus, Jul 31 2013
KEYWORD
base,easy,nonn
AUTHOR
Amarnath Murthy, Nov 16 2002
EXTENSIONS
More terms from Sascha Kurz, Jan 28 2003
STATUS
approved