a(n) = Product_{i=1..n} phi(i) * Sum_{i=1..n} 1/phi(i) where phi is the Euler totient function A000010(n).
A067578
a(n) = Product_{i=1..n} phi(i) * Sum_{i=1..n} 1/phi(i) where phi is the Euler totient function A000010(n).
Terms
- a(0) =1a(1) =2a(2) =5a(3) =12a(4) =52a(5) =120a(6) =752a(7) =3200a(8) =19968a(9) =84480a(10) =863232a(11) =3637248a(12) =44384256a(13) =275152896a(14) =2254307328a(15) =18459131904a(16) =298743496704
External references
- oeis: A067578