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Search: id:A006939
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| A006939 |
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Chernoff sequence: a(n) = Product_{k=1..n} prime(k)^(n-k+1).
(Formerly M2050)
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+0
19
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| 1, 2, 12, 360, 75600, 174636000, 5244319080000, 2677277333530800000, 25968760179275365452000000, 5793445238736255798985527240000000, 37481813439427687898244906452608585200000000, 7517370874372838151564668004911177464757864076000000000, 55784440720968513813368002533861454979548176771615744085560000000000
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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Product of first n primorials: a(n)=Product[A002110(n)],j=1..n.
Superprimorials, from primorials by analogy with superfactorials.
Smallest number with n distinct exponents in its prime factorization.
Subsequence of A130091. - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 06 2007
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REFERENCES
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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
C. Pickover, Mazes for the Mind, St. Martin's Press, NY, 1992, p. 351.
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LINKS
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T. D. Noe, Table of n, a(n) for n=0..25
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FORMULA
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a(n) = m(1)*m(2)*m(3)*...*m(n), where m(n) = n-th primorial number
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EXAMPLE
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a(4) = 360 because 1*2*6*30 = 360
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MAPLE
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a := []; printlevel := -1; for k from 1 to 20 do a := [op(a), product(ithprime(i)^(k-i+1), i=1..k)] od; print(a);
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CROSSREFS
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Cf. A000178 (product of first n factorials), A007489 (sum of first n factorials), A060389 (sum of first n primorials).
Cf. A002110, A051357.
Sequence in context: A061307 A061300 A079264 this_sequence A152686 A131690 A158261
Adjacent sequences: A006936 A006937 A006938 this_sequence A006940 A006941 A006942
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KEYWORD
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easy,nonn,nice
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
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Corrected and extended by Labos E. (labos(AT)ana.sote.hu), May 30 2001
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