A077681 - OEIS

A077681

Squarefree numbers beginning with 5.

5, 51, 53, 55, 57, 58, 59, 501, 502, 503, 505, 506, 509, 510, 511, 514, 515, 517, 518, 519, 521, 523, 526, 527, 530, 533, 534, 535, 537, 538, 541, 542, 543, 545, 546, 547, 551, 553, 554, 555, 557, 559, 561, 562, 563, 565, 566, 569, 570, 571, 573, 574, 577

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Lower density is 3/(25*Pi^2), upper density is 10/(9*Pi^2). - Charles R Greathouse IV, Nov 05 2017

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..5000

MATHEMATICA

Table[Select[Range[5*10^n, 6*10^n-1], SquareFreeQ], {n, 0, 2}]//Flatten (* Harvey P. Dale, Apr 15 2017 *)

PROG

(PARI) is(n)=n>4 && digits(n)[1]==5 && issquarefree(n) \\ Charles R Greathouse IV, Nov 05 2017

CROSSREFS