A124301 - OEIS

%I #18 Oct 08 2024 15:07:36

%S 1,2,29,242,844,22020,217070,1092747,8870024,221167422,221167422

%N Smallest number m such that A124300(m) >= n.

%C A008683(a(n) + k) = A008683(a(n)) for 0<=k<=n.

%e a(4) = 844:

%e mu(844) = mu(2*2*211) = 0;

%e mu(844+1) = mu(5*13*13) = 0;

%e mu(844+2) = mu(2*3*3*47) = 0;

%e mu(844+3) = mu(7*11*11) = 0;

%e mu(844+4) = mu(2*2*2*2*53) = 0.

%o (PARI) a(n)={x=1;k=moebius(x);y=n+x;while(x<y,x++;if(moebius(x)!=k,k=moebius(x);y=x+n));x-n} \\ _Jinyuan Wang_, Apr 06 2019

%o (Python)

%o from itertools import count

%o from sympy import mobius

%o def A124301(n):

%o     c, m = 1, 1

%o     for i in count(2):

%o         k = mobius(i)

%o         if m!=k:

%o             if c>n:

%o                 return i-c

%o             c = 0

%o         c += 1

%o         m = k # _Chai Wah Wu_, Oct 08 2024

%Y Cf. A008683 (Möbius function mu), A124300.

%K nonn,more

%O 0,2

%A _Reinhard Zumkeller_, Oct 25 2006

%E a(7)-a(8) from Peter T. Wang (peterw(AT)ugcs.caltech.edu), Feb 04 2007

%E Name edited by and a(9)-a(10) from _Jinyuan Wang_, Apr 06 2019