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A110373
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a(n) = Sum_{prime p <= n} n!/p.
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7
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1, 5, 20, 124, 744, 5928, 47424, 426816, 4268160, 50578560, 606942720, 8369256960, 117169597440, 1757543961600, 28120703385600, 498974747443200, 8981545453977600, 177051737331302400, 3541034746626048000
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OFFSET
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2,2
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LINKS
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EXAMPLE
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a(7) = 7!(1/2 + 1/3 + 1/5 + 1/7) = 5928.
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MAPLE
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a:=proc(n) local s, i: s:=0: for i from 2 to n do if isprime(i)=true then s:=s+1/i else s:=s: fi: od: n!*s: end: seq(a(n), n=2..23); # Emeric Deutsch, Jul 24 2005
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MATHEMATICA
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Table[n! Total[1/Prime[Range[PrimePi[n]]]], {n, 20}] (* Harvey P. Dale, Mar 06 2017 *)
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CROSSREFS
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KEYWORD
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easy,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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