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A127601
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Integer part of 4th root of product of first n primes.
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5
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1, 1, 1, 2, 3, 6, 13, 26, 55, 122, 283, 669, 1650, 4176, 10694, 28002, 75555, 209402, 585212, 1674296, 4860120, 14206194, 42353033, 127836257, 392646335, 1232237672, 3906383039, 12444691408, 40024883480, 129326254765
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OFFSET
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0,4
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COMMENTS
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For n>=6, a(n) >= prime(n+1).
a(n) gives the number of pairs within A002110(n) of the form {x, x^4} where x is nonzero positive integer. - Soumyadeep Dhar, May 16 2021
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LINKS
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MATHEMATICA
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a = {}; Do[b = 1; Do[b = b Prime[x], {x, 1, n}]; AppendTo[a, Floor[b^(1/4)]], {n, 1, 50}]; a
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PROG
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(PARI) a(n)={sqrtnint(vecprod(primes(n)), 4)} \\ Andrew Howroyd, Apr 27 2021
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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