OFFSET
1,1
COMMENTS
Arguably a(1)=3, as the multiplicative group mod 2 has only one element, hence its factorization is the empty product. - Joerg Arndt, May 18 2018
For n >= 2, positions of records of A046072. - Joerg Arndt, May 18 2018
FORMULA
PROG
(PARI) a(n)=if(n==1, 2, 4*prod(k=1, n-1, prime(k)));
CROSSREFS
KEYWORD
nonn
AUTHOR
Joerg Arndt, May 05 2016
STATUS
approved