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 A171435 Product of odd prime factors < n, with multiplicity. 2
 1, 1, 1, 1, 1, 3, 1, 1, 9, 5, 1, 3, 1, 7, 15, 1, 1, 9, 1, 5, 21, 11, 1, 3, 25, 13, 27, 7, 1, 15, 1, 1, 33, 17, 35, 9, 1, 19, 39, 5, 1, 21, 1, 11, 45, 23, 1, 3, 49, 25, 51, 13, 1, 27, 55, 7, 57, 29, 1, 15, 1, 31, 63, 1, 65, 33, 1, 17, 69, 35, 1, 9, 1, 37, 75, 19, 77, 39, 1, 5, 81, 41, 1, 21, 85 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,6 COMMENTS In this sequence p < n, but p^k with k>=2 may be equal to n. a(n) = 1 iff n = 2^k, k >= 0 or n is prime; 1 < a(n) < n iff n is even composite and not a power of 2; a(n) = n iff n is nonprime (unit or composite) odd. LINKS Daniel Forgues, Table of n, a(n) for n=1..100000 CROSSREFS Cf. A171487, A000265, A010051. Sequence in context: A142992 A145905 A336859 * A144183 A050153 A294950 Adjacent sequences:  A171432 A171433 A171434 * A171436 A171437 A171438 KEYWORD nonn AUTHOR Daniel Forgues, Dec 09 2009 EXTENSIONS Edited by Daniel Forgues, Dec 10 2009 STATUS approved

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Last modified April 11 00:03 EDT 2021. Contains 342877 sequences. (Running on oeis4.)