login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A318304 a(n) = A083254(n)/A003557(n) = (2*A173557(n) - A007947(n)). 3
1, 0, 1, 0, 3, -2, 5, 0, 1, -2, 9, -2, 11, -2, 1, 0, 15, -2, 17, -2, 3, -2, 21, -2, 3, -2, 1, -2, 27, -14, 29, 0, 7, -2, 13, -2, 35, -2, 9, -2, 39, -18, 41, -2, 1, -2, 45, -2, 5, -2, 13, -2, 51, -2, 25, -2, 15, -2, 57, -14, 59, -2, 3, 0, 31, -26, 65, -2, 19, -22, 69, -2, 71, -2, 1, -2, 43, -30, 77, -2, 1, -2, 81, -18, 43, -2, 25 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..65537

FORMULA

a(n) = A083254(n)/A003557(n) = 2*A173557(n) - A007947(n).

a(n) = A173557(n) - A318305(n).

PROG

(PARI)

A173557(n) = my(f=factor(n)[, 1]); prod(k=1, #f, f[k]-1); \\ From A173557

A007947(n) = factorback(factorint(n)[, 1]); \\ From A007947

A318304(n) = (2*A173557(n) - A007947(n));

(PARI)

A083254(n) = (2*eulerphi(n)-n);

A003557(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 2] = f[i, 2]-1); factorback(f); }; \\ From A003557

A318304(n) = (A083254(n)/A003557(n));

CROSSREFS

Cf. A000010, A003557, A007947, A083254, A173557, A318305.

Sequence in context: A185390 A019116 A213611 * A318989 A082493 A323912

Adjacent sequences:  A318301 A318302 A318303 * A318305 A318306 A318307

KEYWORD

sign

AUTHOR

Antti Karttunen, Aug 26 2018

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 24 04:20 EDT 2019. Contains 322406 sequences. (Running on oeis4.)