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A180617
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Sum of divisors of the product of two consecutive primes.
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3
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12, 24, 48, 96, 168, 252, 360, 480, 720, 960, 1216, 1596, 1848, 2112, 2592, 3240, 3720, 4216, 4896, 5328, 5920, 6720, 7560, 8820, 9996, 10608, 11232, 11880, 12540, 14592, 16896, 18216, 19320, 21000, 22800, 24016, 25912, 27552, 29232, 31320, 32760, 34944, 37248, 38412
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OFFSET
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1,1
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LINKS
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FORMULA
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EXAMPLE
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a(1) = sigma(2*3) = 12, a(2) = sigma(3*5) = 24.
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MATHEMATICA
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DivisorSigma[1, #]&/@(Times@@@Partition[Prime[Range[50]], 2, 1]) (* Harvey P. Dale, Apr 04 2015 *)
Table[Prime[n]*Prime[n+1]+Prime[n]+Prime[n+1]+1, {n, 1, 30}] (* Metin Sariyar, Dec 08 2019 *)
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PROG
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(PARI) for (n=1, 10, i=prod(x=n, n+1, prime(x)); p=sigma(i); print1(p, ", "); )
(Magma) [(1+NthPrime(n))*(1+NthPrime(n+1)): n in [1..50]]; // Vincenzo Librandi, Feb 16 2015
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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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