A069859 (Largest prime factor of n) modulo (smallest prime factor of n).

0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 2, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 2, 1, 2, 1, 0, 1, 1, 1, 0, 1, 0, 1, 2, 1, 0, 1, 0, 1, 2, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 3, 1, 0, 1, 2, 1, 0, 1, 0, 1, 2, 1, 4, 1, 0, 1, 0, 1, 0, 1, 2, 1, 2, 1, 0, 1, 6, 1, 1, 1, 4, 1, 0, 1, 2, 1, 0, 1, 0, 1, 1

Offset: 1

Author

Reinhard Zumkeller, Apr 23 2002

Keywords

• nonn
• look

Comments

a(n) = A006530(n) - A069897(n)*A020639(n).

Links

• Antti Karttunen, Table of n, a(n) for n = 1..65537

Crossrefs

Cf. A006530, A020639, A046665, A069897.

Programs

Mathematica

lpfmspf[n_]:=Module[{fs=Transpose[FactorInteger[n]][[1]]},Mod[Last[fs], First[fs]]]; Array[lpfmspf,100] (* Harvey P. Dale, Jul 10 2015 *)

PARI

A069859(n) = if(1==n,0, my(f = factor(n), lpf = f[1, 1], gpf = f[#f~, 1]); (gpf%lpf)); \\ Antti Karttunen, Sep 25 2018

Formula

a(n) = A006530(n) mod A020639(n).

Extensions

More terms from Antti Karttunen, Sep 25 2018