The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

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