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Search: id:A077622
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| A077622 |
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Number of numbers <= prime(n)# having n prime factors, where prime(n)# = A002110(n) is the n-th primorial. |
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+0
4
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| 1, 2, 7, 27, 190, 1621, 17271, 200536, 2757881, 47108763, 843069901
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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a(n) = A077618(A002110(n)), see A077621.
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EXAMPLE
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a(3)=7, as there are 7 numbers <= prime(3)# = 2*3*5 = 30 having 3 prime factors: 8=2*2*2, 12=2*2*3, 18=2*3*3, 20=2*2*5, 27=3*3*3, 28=2*2*7 and 30=2*3*5.
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CROSSREFS
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Cf. A001222.
Sequence in context: A150645 A060017 A058800 this_sequence A137108 A099815 A123363
Adjacent sequences: A077619 A077620 A077621 this_sequence A077623 A077624 A077625
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KEYWORD
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nonn,new
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AUTHOR
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Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Nov 12 2002
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EXTENSIONS
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17271 from Sascha Kurz (sascha.kurz(AT)uni-bayreuth.de), Jan 04 2003
a(8)-a(11) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Nov 15 2009
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