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A333373
a(n) = n + 1 for n <= 1; thereafter a(n) = a(n-1) * prime(gpf(a(n-1))).
0
1, 2, 6, 30, 330, 10230, 1299210, 921139890, 4956653748090, 261270175715571990, 169405230502395438168090, 1649555141343581679123602303970, 287748466487735183193170029972221262770, 1052440045241486547790272887133572295775622539770
OFFSET
0,2
COMMENTS
For n > 1, a(n) belongs to A083207 (see "product" formula below and my Jan 16 2020 comment in A083207). - Ivan N. Ianakiev, Mar 17 2020
FORMULA
a(n) = Product_{k=0..n} A007097(k).
A156061(a(n+1)) = a(n).
A052126(a(n+1)) = a(n).
EXAMPLE
a(7) = a(6) * prime(gpf(a(6))) = prime(1) * prime(2) * prime(3) * prime(5) * prime(11) * prime(31) * prime(127) = 2 * 3 * 5 * 11 * 31 * 127 * 709 = 921139890.
MATHEMATICA
a[0] = 1; a[n_] := a[n] = a[n - 1] Prime[FactorInteger[a[n - 1]][[-1, 1]]]; Table[a[n], {n, 0, 13}]
Table[Times @@ NestList[Prime@# &, 1, n], {n, 0, 13}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Mar 17 2020
STATUS
approved