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A066120
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Superduperprimorials: product of first n terms in Chernoff sequence.
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12
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OFFSET
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0,2
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COMMENTS
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First number with n distinct positive triangular exponents in its prime factorization. Subsequence of A025487. - Matthew Vandermast, Nov 05 2009; edited May 23 2012
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LINKS
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FORMULA
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a(n) = Product_{i=1..n} prime(i)^((n-i+1)*(n-i+2)/2) = a(n-1)*A006939(n) = A066119(n-3, 4).
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EXAMPLE
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a(4) = 2*(2*(2*3))*(2*(2*3)*(2*3*5)) = 2*(2*6)*(2*6*30) = 2*12*360 = 8640.
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PROG
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(PARI) { for (n=0, 17, a=1; for(i=1, n, a*=prime(i)^((n - i + 1)*(n - i + 2)/2)); write("b066120.txt", n, " ", a) ) } \\ Harry J. Smith, Feb 01 2010
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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