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A137427 Squarefree part of partial sum of squarefree part of n. 1
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; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Core(partial sum(core(n))) where "core" means "squarefree part."

LINKS

Table of n, a(n) for n=1..61.

FORMULA

a(n)=A007913(A069891(n)). - R. J. Mathar, Apr 23 2008

EXAMPLE

a(35) = 1 because A007913( A069891(35) ) = A007913(441) = A007913(21^2) = 1.

MAPLE

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, Apr 23 2008

CROSSREFS

Cf. A007913, A069891.

Sequence in context: A275696 A080260 A065269 * A177035 A055102 A243976

Adjacent sequences:  A137424 A137425 A137426 * A137428 A137429 A137430

KEYWORD

easy,nonn

AUTHOR

Jonathan Vos Post, Apr 17 2008

EXTENSIONS

Edited and extended by R. J. Mathar, Apr 23 2008

STATUS

approved

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Last modified September 25 12:38 EDT 2021. Contains 347654 sequences. (Running on oeis4.)