A075393 Positive integers k that are not divisible by A002034(k).

9, 16, 25, 45, 49, 75, 80, 121, 125, 147, 169, 175, 225, 243, 245, 250, 256, 289, 343, 361, 363, 441, 486, 500, 507, 512, 525, 529, 539, 605, 625, 637, 675, 686, 729, 735, 768, 841, 845, 847, 867, 875, 961, 1000, 1024, 1083, 1089, 1183, 1215, 1225, 1250

Offset

1,1

Comments

If k is squarefree, then A002034(k) is the largest prime factor of k, so k is not in the sequence. If p is an odd prime, then A002034(p^2) = 2*p, so p^2 is in the sequence. - David Wasserman, Jan 17 2005

Links

Amiram Eldar, Table of n, a(n) for n = 1..1000

Example

a(1)=9 because 9 is the first number that is not a multiple of A002034(9)=6.

Mathematica

(A002034[n_] := (m=1; While[ !IntegerQ[m!/n], m++ ]; m); list = {}; Do[If[ !IntegerQ[n/A002034[n]], list = Append[list, n]], {n, 100}]; list) (* Jonathan Sondow, Apr 18 2004 *)

Crossrefs

Cf. A002034.

Sequence in context: A177430 A256705 A092941 * A336449 A161183 A183345

Adjacent sequences: A075390 A075391 A075392 * A075394 A075395 A075396

Keyword

nonn

Author

Amarnath Murthy, Sep 22 2002

Extensions

More terms from David Wasserman, Jan 17 2005

Edited by N. J. A. Sloane, Apr 19 2007

Status

approved