OFFSET
1,3
COMMENTS
This sequence has similarities with A038554; here we consider prime exponents, there binary digits.
FORMULA
PROG
(PARI) a(n) = { my (v=1, p=2, e=valuation(n, p)); n/=p^e; forprime (q=p+1, oo, if (n==1, return (v), my (f=valuation(n, q)); n/=q^f; v*=p^bitxor(e, f); [p, e]=[q, f])) }
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, May 18 2020
STATUS
approved