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A074167
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Product of prime divisors of composite numbers between consecutive primes.
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2
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1, 2, 6, 60, 6, 420, 6, 4620, 32760, 30, 471240, 14820, 42, 15180, 556920, 15273720, 30, 11171160, 164220, 6, 253333080, 2460, 587636280, 625757605200, 4620, 102, 289380, 6, 170940, 26848135265397670224000, 33540, 599888520, 138, 39560762839197600, 30
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OFFSET
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1,2
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LINKS
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FORMULA
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EXAMPLE
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a(4) = product of prime factors of composite numbers between 7 and 11 = 2 * 3 * (2 * 5) = 60.
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MAPLE
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a:= n-> mul(mul(i[1], i=ifactors(j)[2]), j=ithprime(n)+1..ithprime(n+1)-1):
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MATHEMATICA
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Array[Times @@ Flatten@ Map[FactorInteger[#][[All, 1]] &, Range[#1 + 1, #2 - 1]] & @@ Prime[{#, # + 1}] &, 35] (* Michael De Vlieger, May 29 2022 *)
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PROG
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(PARI) a(n) = my(p=1); forcomposite(c=prime(n), prime(n+1), p*=factorback(factorint(c)[, 1])); p; \\ Michel Marcus, May 29 2022
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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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