A077679 Squarefree numbers beginning with 3.

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

Harvey P. Dale, Table of n, a(n) for n = 1..1000

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

Crossrefs

Cf. A077677, A077678, A077680, A077681, A077682, A077683, A077684, A077685.

Sequence in context: A295430 A344430 A217395 * A045863 A121023 A124520

Adjacent sequences: A077676 A077677 A077678 * A077680 A077681 A077682

Keyword

base,easy,nonn

Author

Amarnath Murthy, Nov 16 2002

Extensions

More terms from Sascha Kurz, Jan 28 2003

Status

approved