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A113498
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Ascending descending base exponent transform of omega(n) [A001221].
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4
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1, 2, 3, 4, 6, 7, 8, 9, 13, 12, 14, 15, 21, 19, 21
(list; graph; refs; listen; history; internal format)
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OFFSET
| 2,2
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FORMULA
| a(n) = SUM[from i = 1 to n] omega(n+1). a(n) = SUM[from i = 2 to n+1] number of distinct primes dividing i. a(n) = SUM[from i = 1 to n] A001221(n+1).
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EXAMPLE
| Since omega(n) = A001221(n) = 0, 1, 1, 1, 1, 2, 1, 1, 1, 2 and we skip the initial zero term, we have:
a(1) = 1^1 = 1.
a(2) = 1^1 + 1^1 = 2.
a(3) = 1^1 + 1^1 + 1^1 = 3.
a(4) = 1^1 + 1^1 + 1^1 + 1^1 = 4.
a(5) = 1^1 + 1^1 + 1^1 + 1^1 + 2^1 = 6.
a(9) = 1^1 + 1^1 + 1^1 + 1^1 + 2^2 + 1^1 + 1^1 + 1^1 + 2^1 = 13.
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CROSSREFS
| Cf. A001221, A113320, A005408, A113122, A113153, A113154, A113336, A113271, A113258, A113257, A113231, A087316, A113208.
Sequence in context: A134003 A128170 A018490 * A036796 A039123 A131618
Adjacent sequences: A113495 A113496 A113497 * A113499 A113500 A113501
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KEYWORD
| easy,nonn
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AUTHOR
| Jonathan Vos Post (jvospost3(AT)gmail.com), Jan 10 2006
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