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A346091
a(n) = A328571(A108951(n)).
7
2, 3, 5, 3, 7, 5, 11, 15, 35, 7, 13, 5, 17, 11, 7, 15, 19, 35, 23, 7, 11, 13, 29, 35, 77, 17, 55, 11, 31, 77, 37, 21, 13, 19, 143, 35, 41, 23, 17, 77, 43, 143, 47, 13, 77, 29, 53, 35, 2431, 77, 19, 17, 59, 55, 221, 11, 23, 31, 61, 77, 67, 37, 143, 21, 323, 13, 71, 19, 29, 143, 73, 385, 79, 41, 1001, 23, 221, 17, 83, 77, 385
OFFSET
1,1
COMMENTS
All terms are squarefree (in A005117). - Antti Karttunen, Apr 03 2022
FORMULA
a(n) = A324886(n) / A344592(n).
For all n >= 1, a(A000040(n)) = A000040(1+n).
PROG
(PARI)
A002110(n) = prod(i=1, n, prime(i));
A108951(n) = { my(f=factor(n)); prod(i=1, #f~, A002110(primepi(f[i, 1]))^f[i, 2]) };
A328571(n) = { my(m=1, p=2); while(n, m *= (p^!!(n%p)); n = n\p; p = nextprime(1+p)); (m); };
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jul 09 2021
STATUS
approved