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

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

Cf. A077677, A077678, A077679, A077680, A077682, A077683, A077684, A077685.

Sequence in context: A063803 A106425 A160779 * A326738 A322927 A333261

Adjacent sequences: A077678 A077679 A077680 * A077682 A077683 A077684

Keyword

base,easy,nonn

Author

Amarnath Murthy, Nov 16 2002

Extensions

More terms from Sascha Kurz, Jan 28 2003

Status

approved