OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..2370
FORMULA
If n = 2^e_1 * 3^e_2 * ... * prime(k)^e_k, then a(n) = 2^max(e_1, e_2, ..., e_k) * 3^max(e_2, ..., e_k) * ... * prime(k-1)^max(e_{k-1}, e_k) * prime(k)^e_k = lcm_{i=1}^k prime(k)#^e_k. In particular, if p prime, a(p) = p# (primorial, A002110). When gcd(n,m) = 1, a(n*m) = lcm(a(n), a(m)). Also, a(n^k) = a(n)^k. - Franklin T. Adams-Watters, Oct 24 2006
MATHEMATICA
prim[p_] := Product[Prime[i], {i, PrimePi[p]}]; a[n_] := Module[{f = FactorInteger[n]}, p = f[[;; , 1]]; e = f[[;; , 2]]; LCM @@ ((prim /@ p)^e)]; Array[a, 50] (* Amiram Eldar, Dec 30 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Jeff Burch, Aug 22 2002
STATUS
approved