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A135369
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a(0)=1, a(1)=2; thereafter, let n! = p(1)^b(1)...p(r)^b(r) be the prime factorization of n!. Then a(n) = Sum_{i=1..r} (p(i) + b(i)).
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1
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1, 2, 3, 7, 9, 15, 17, 25, 28, 30, 32, 44, 47, 61, 63, 65, 69, 87, 90, 110, 113, 115, 117, 141, 145, 147, 149, 152, 155, 185, 188, 220, 225, 227, 229, 231, 235, 273, 275, 277, 281, 323, 326, 370, 373, 376, 378, 426, 431, 433, 436, 438, 441, 495, 499, 501, 505
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OFFSET
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0,2
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LINKS
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FORMULA
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MAPLE
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A001222 := proc(n) numtheory[bigomega](n) ; end:
A008472 := proc(n) add(op(1, i), i=ifactors(n)[2]) ; end:
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MATHEMATICA
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Join[{1}, Table[Total[Flatten[FactorInteger[n!]]], {n, 60}]] (* Harvey P. Dale, Feb 26 2012 *)
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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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