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Search: id:A137427
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| A137427 |
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Squarefree part of partial sum of squarefree part of n. |
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+0
1
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| 1, 3, 6, 7, 3, 2, 1, 3, 7, 38, 1, 13, 65, 79, 94, 95, 7, 114, 133, 138, 159, 181, 51, 210, 211, 237, 15, 247, 69, 34, 337, 339, 93, 406, 1, 442, 479, 517, 139, 566, 607, 649, 173, 703, 177, 754, 89, 201, 805, 807, 858, 871, 231, 930, 985, 111, 66, 1114, 1173, 33, 1249
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Core(partial sum(core(n))) where "core" means "squarefree part."
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FORMULA
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a(n)=A007913(A069891(n)). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 23 2008
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EXAMPLE
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a(35) = 1 because A007913( A069891(35) ) = A007913(441) = A007913(21^2) =1 .
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MAPLE
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A007913 := proc(n) local a, f ; a := 1 ; for f in ifactors(n)[2] do if op(2, f) mod 2 <> 0 then a := a*op(1, f) ; fi ; od: a ; end: A069891 := proc(n) add( A007913(k), k=1..n) ; end: A137427 := proc(n) A007913(A069891(n)) ; end: seq(A137427(n), n=1..100) ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 23 2008
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CROSSREFS
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Cf. A007913, A069891.
Sequence in context: A133329 A080260 A065269 this_sequence A055102 A098990 A117361
Adjacent sequences: A137424 A137425 A137426 this_sequence A137428 A137429 A137430
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KEYWORD
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easy,nonn
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AUTHOR
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Jonathan Vos Post (jvospost3(AT)gmail.com), Apr 17 2008
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EXTENSIONS
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Edited and extended by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 23 2008
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