89813529domain: NAppears in sequencesa(n) = Product_{k=1..n-1} gcd(k,n).at n=38A051190Number of spanning trees on the bipartite graph K_{3,n}.at n=13A069996Smallest odd n-almost prime m such that m-2 and m+2 are both prime (cousin primes).at n=13A145031Sequence related to discriminant of cyclotomic polynomials A004124.at n=38A193679