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1, 1, 2, 4, 6, 4, 10, 12, 16, 18, 22, 12, 3, 28, 30, 36, 3, 40, 42, 4, 46, 24, 52, 58, 60, 66, 70, 72, 78, 20, 82, 88, 96, 100, 102, 106, 108, 112, 60, 126, 130, 136, 138, 148, 150, 8, 156, 162, 166, 84, 172, 178, 180, 190, 192, 196, 198, 210, 222, 7, 226, 228, 232, 238
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OFFSET
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1,3
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COMMENTS
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For n > 1, a(n) gives the unique solution k of d(n^k) = n where d = A000005. For n = 1, any integer k will do, we choose the smallest positive solution a(1) = 1.
For prime p, p-1 is in this sequence.
For odd semiprime s, (s-1)/2 is in this sequence.
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LINKS
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D. W. Wilson, Table of n, a(n) for n=1..10000
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EXAMPLE
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11^10 has 11 divisors, so a(n) = 10 where A180934(n) = 11.
225^7 has 225 divisors, so a(n) = 7 where A180934(n) = 225.
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CROSSREFS
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Cf. A000005, A180934, A180936
Sequence in context: A360458 A074320 A014428 * A151886 A334016 A278259
Adjacent sequences: A180932 A180933 A180934 * A180936 A180937 A180938
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KEYWORD
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nonn
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AUTHOR
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David W. Wilson, Sep 26 2010
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STATUS
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approved
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