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 A181820 a(1) =1; for n>1, if A025487(n) = Product p(i)^e(i), then a(n) = Product p(e(i)). 8
 1, 2, 3, 4, 5, 6, 7, 10, 8, 11, 9, 14, 12, 13, 15, 22, 20, 17, 21, 18, 26, 16, 25, 28, 19, 33, 30, 34, 24, 35, 44, 23, 39, 42, 38, 40, 55, 27, 52, 29, 50, 51, 36, 49, 66, 46, 56, 65, 45, 68, 31, 70, 57, 32, 60, 77, 78, 58, 88, 85, 63, 76, 37, 110, 69, 48, 84, 91, 75, 102, 62, 54, 98, 104, 95 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS A permutation of the natural numbers. LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 FORMULA a(n)=A181819(A025487(n)). a(n)=A122111(A181815(n)). EXAMPLE A025487(8) = 24 = 2^3*3 has the exponents (3,1) in its canonical prime factorization. Accordingly, a(8) = prime(3)*prime(1) (i.e., A000040(3)*A000040(1)), which equals 5*2=10. CROSSREFS A181815 is another mapping from the members of A025487 to the positive integers. Also see A181819, A181821. Sequence in context: A084690 A194963 A072794 * A199426 A119257 A266645 Adjacent sequences:  A181817 A181818 A181819 * A181821 A181822 A181823 KEYWORD nonn AUTHOR Matthew Vandermast, Dec 07 2010 STATUS approved

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Last modified November 28 07:44 EST 2020. Contains 338702 sequences. (Running on oeis4.)