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A123567
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Recursive sum of 2*Omega(n), where Omega(n) is the sequence A001222.
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0
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3, 5, 7, 11, 13, 17, 19, 25, 29, 33, 35, 41, 43, 47, 51, 59, 61, 67, 69, 75, 79, 83, 85, 93, 97, 101, 107, 113, 115, 121, 123, 133, 137, 141, 145, 153, 155, 159, 163, 171, 173, 179, 181, 187, 193, 197, 199, 209, 213, 219, 223, 229, 231, 239, 243, 251, 255, 259, 261
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Note that the first 7 terms are prime numbers. See also the sum of Omega (A022559).
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FORMULA
| a(n+1)=a(n)+ 2*A001222(n), with a(1)=3.
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EXAMPLE
| a(2)=a(1)+2*Omega(1)=3+2=5;
a(3)=a(2)+2*Omega(2)=5+2=7;
a(4)=a(3)+2*Omega(3)=7+4=11;
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MATHEMATICA
| Omega = Plus @@ Sum[Transpose[FactorInteger[ # ]][[2]]] &; FoldList[Plus, 3, 2Map[Omega, Range[2, 200]]]
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CROSSREFS
| Sequence in context: A131261 A100276 A065389 * A059645 A090190 A065041
Adjacent sequences: A123564 A123565 A123566 * A123568 A123569 A123570
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KEYWORD
| nonn
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AUTHOR
| Carlos Alves (cjsalves(AT)gmail.com), Nov 12 2006
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