OFFSET
2,2
LINKS
Tyler Busby, Table of n, a(n) for n = 2..159 (terms 2..74 from Amiram Eldar, terms 75..145 from Max Alekseyev)
Reinhard Zumkeller, Products of largest prime factors of numbers <= n
MATHEMATICA
a[n_] := FactorInteger[-1 + Product[FactorInteger[k][[-1, 1]], {k, 1, n}]][[-1, 1]]; Array[a, 50, 2] (* Amiram Eldar, Feb 12 2020 *)
PROG
(PARI) gpf(n) = if (n==1, 1, vecmax(factor(n)[, 1])); \\ A006530
a(n) = gpf(prod(i=2, n, gpf(i))-1); \\ Michel Marcus, Feb 21 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Mar 06 2005
STATUS
approved