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A055038
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Number of numbers <= n with an odd number of prime factors (counted with multiplicity).
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2
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0, 1, 2, 2, 3, 3, 4, 5, 5, 5, 6, 7, 8, 8, 8, 8, 9, 10, 11, 12, 12, 12, 13, 13, 13, 13, 14, 15, 16, 17, 18, 19, 19, 19, 19, 19, 20, 20, 20, 20, 21, 22, 23, 24, 25, 25, 26, 27, 27, 28, 28, 29, 30, 30, 30, 30, 30, 30, 31, 31, 32, 32, 33, 33, 33, 34, 35, 36, 36, 37, 38, 39, 40, 40, 41
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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COMMENTS
| Partial sums of A066829.
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LINKS
| Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Polya Conjecture
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FORMULA
| 1/2*Sum_{k=1..n} (1-lambda(k))= (1/2) *(n-L(n)), where lambda(n)=A008836(n) and L(n)=A002819(n).
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PROG
| (Haskell)
a055038 n = a055038_list !! (n-1)
a055038_list = scanl1 (+) a066829_list
-- Reinhard Zumkeller, Nov 19 2011
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CROSSREFS
| Cf. A001222, A055037.
Sequence in context: A082997 A085970 A066683 * A085268 A194979 A098294
Adjacent sequences: A055035 A055036 A055037 * A055039 A055040 A055041
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KEYWORD
| nonn
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AUTHOR
| Antreas P. Hatzipolakis (xpolakis(AT)otenet.gr), Jun 01 2000
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EXTENSIONS
| Formula and more terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Dec 03 2001
Offset corrected by Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Nov 19 2011
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