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Search: id:A135369
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| A135369 |
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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
(list; graph; listen)
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OFFSET
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0,2
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FORMULA
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a(n) = A008474(n!) if n>1. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 28 2008
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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: A008474 := proc(n) A001222(n)+A008472(n) ; end: A135369 := proc(n) if n < 2 then n+1 ; else A008474(n!) ; fi ; end: seq(A135369(n), n=0..80) ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 28 2008
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CROSSREFS
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Cf. A000142.
Sequence in context: A096072 A014837 A019312 this_sequence A109660 A075855 A140189
Adjacent sequences: A135366 A135367 A135368 this_sequence A135370 A135371 A135372
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KEYWORD
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easy,nonn
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AUTHOR
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Ctibor O. ZIZKA (ctibor.zizka(AT)seznam.cz), Feb 17 2008
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EXTENSIONS
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More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 28 2008
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