A073904(2^n) is the product of the first n members of this sequence. Problem Generalite A073904(p^n) analogous: permutation of the numbers of the form q^(p^k), such that a(p^j)=p^(p^j); A073904(p^n)=(produkt of the first n members)^(p-1). - David WASSERMAN & Tom ORDO
FORMULA
a(2^j)=2^(2^j). So a(1)=2 for j=0; a(2)=4 for j=1; a(4)=16 for j=2