OFFSET
1,7
COMMENTS
Weak conjecture: sequence gives positive values only; strong conjecture: for n large enough a(n) > 2*sqrt(n).
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
Robert Israel, Log-log plot of (n, a(n)) for 1 <= n <= 10^6
FORMULA
MAPLE
f:= proc(n) local t; t:= max(numtheory:-factorset(n)) mod 4; if t = 3 then 1 elif t= 1 then -1 else 0 fi end proc:
ListTools:-PartialSums(map(f, [$1..100])); # Robert Israel, Nov 05 2024
PROG
(PARI) for(n=1, 200, print1(sum(i=2, n, if((component(component(factor(i), 1), omega(i))-3)%4, 0, 1))-sum(i=2, n, if((component(component(factor(i), 1), omega(i))-1)%4, 0, 1)), ", "))
CROSSREFS
KEYWORD
AUTHOR
Benoit Cloitre, Jun 07 2002
EXTENSIONS
Missing a(1)=0 inserted by Sean A. Irvine, Aug 16 2024
STATUS
approved