35389440
domain: N
Appears in sequences
- a(n) = Product_{k=1..n} d(k); d(k) = A000005(k) is the number of positive divisors of k.at n=17A066843
- Commuting elements: number of ordered pairs g, h in the group GL(2,Z_n) such that gh = hg.at n=23A070943
- a(n) = 2^(n(n-1)/2) * Product_{k=1..n} k!.at n=5A098695
- Consider the Watanabe tag system defined in A291067; a(n) = number of binary words of length n which terminate in a cycle.at n=25A291781
- a(n) = Product_{k=1..n} phi(prime(k)-1).at n=12A338364