A249016 - OEIS

%I #11 Nov 11 2024 22:22:57

%S 1,2,3,5,13,17,21,23,33,42,43,56,57,75,84,99,101,105,109,119,133,139,

%T 157,162,163,182,183,207,208,219,220,255,257,263,267,303,305,307,315,

%U 340,341,343,383,385,387,397,411,420,421,423,469,483,485,489,505,519,523,547,552,553,581,602,603,609,618

%N Indices of records in A055460 (number of primes dividing the squarefree part of n!).

%H Max Alekseyev, <a href="/A249016/b249016.txt">Table of n, a(n) for n = 1..38282</a>

%o (PARI) np=vector(10^6); b=-1; r=0; for(n=1, 10^6, f=factor(n); for(i=1, matsize(f)[1], if(f[i, 2]%2, r += (-1)^np[f[i, 1]]; np[f[i, 1]]=1-np[f[i, 1]]; )); if(r>b, b=r; print1(n, ", ")))

%Y Cf. A249017 (values of records), A055204

%K nonn

%O 1,2

%A _Max Alekseyev_, Oct 19 2014