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A290109 a(1) = 1; for n > 1, a(n) = x1^(x2^(x3^(x4^...))) where x1, x2, ... are the exponents of the primes present (listed from the smallest prime to the largest) in the prime factorization of n. 2
1, 1, 1, 2, 1, 1, 1, 3, 2, 1, 1, 2, 1, 1, 1, 4, 1, 1, 1, 2, 1, 1, 1, 3, 2, 1, 3, 2, 1, 1, 1, 5, 1, 1, 1, 4, 1, 1, 1, 3, 1, 1, 1, 2, 2, 1, 1, 4, 2, 1, 1, 2, 1, 1, 1, 3, 1, 1, 1, 2, 1, 1, 2, 6, 1, 1, 1, 2, 1, 1, 1, 9, 1, 1, 1, 2, 1, 1, 1, 4, 4, 1, 1, 2, 1, 1, 1, 3, 1, 1, 1, 2, 1, 1, 1, 5, 1, 1, 2, 4, 1, 1, 1, 3, 1, 1, 1, 8, 1, 1, 1, 4, 1, 1, 1, 2, 2, 1, 1, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,4
LINKS
FORMULA
a(1) = 1; for n > 1, a(n) = A067029(n) ^ a(A028234(n)).
EXAMPLE
For n = 300 = 2^2 * 3^1 * 5^2 we have a(300) = 2^(1^2) = 2.
For n = 600 = 2^3 * 3^1 * 5^2 we have a(600) = 3^(1^2) = 3.
PROG
(Scheme) (define (A290109 n) (if (= 1 n) 1 (expt (A067029 n) (A290109 (A028234 n))))) ;; Antti Karttunen, Aug 27 2017
CROSSREFS
After a(1) = 1 differs from A087179 for the next time at n=300.
Sequence in context: A182426 A067029 A087179 * A302045 A302035 A307907
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 27 2017
STATUS
approved

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Last modified March 29 06:15 EDT 2024. Contains 371265 sequences. (Running on oeis4.)