This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A292273 For odd n: a(n) = 0, and for even n: a(n) = -mu(n), where mu is Moebius function (A008683). 2
 0, 1, 0, 0, 0, -1, 0, 0, 0, -1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, -1, 0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 0, -1, 0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, -1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1 COMMENTS Sum of Möbius function values computed for terms of 3x+1 trajectory started at n, but excluding mu(n) itself. See Marc LeBrun's comment in A087003. LINKS Antti Karttunen, Table of n, a(n) for n = 1..65537 FORMULA a(n) = (A000035(n)-1) * A008683(n). a(n) = A087003(n) - A008683(n). PROG (PARI) A292273(n) = if(n%2, 0, -moebius(n)); \\ After the definition. \\ Implementation following the Collatz-interpretation: A006370(n) = if(n%2, 3*n+1, n/2); \\ This function from Michael B. Porter, May 29 2010 A087003(n) = { my(s=1); while(n>1, s += moebius(n); n = A006370(n)); (s); }; A292273(n) = (A087003(n)-moebius(n)); \\ Or more directly as: A292273(n) = { my(s=0); while(n>1, n = A006370(n); s += moebius(n)); (s); }; (Scheme) (define (A292273 n) (* (- (A000035 n) 1) (A008683 n))) CROSSREFS Cf. A000035, A006370, A008683, A014682, A039956 (positions of nonzero terms), A087003. Sequence in context: A324539 A324964 A285957 * A324772 A285949 A285530 Adjacent sequences:  A292270 A292271 A292272 * A292274 A292275 A292276 KEYWORD sign AUTHOR Antti Karttunen, Sep 14 2017 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 October 14 01:36 EDT 2019. Contains 327994 sequences. (Running on oeis4.)