The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 60th year, we have over 367,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A319821 a(n) = log_2(A094269(n)). 0
 0, 0, 1, 1, 2, 1, 2, 2, 2, 3, 3, 4, 3, 3, 3, 4, 4, 4, 4, 5, 4, 5, 5, 5, 6, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 7, 7, 8, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 9, 8, 8, 8, 9, 9, 9, 9, 10, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 10, 11, 11, 11, 12 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 COMMENTS A companion sequence of A094269. LINKS Table of n, a(n) for n=1..82. FORMULA phi(A003401(n)) = A094269(n) = 2^a(n). PROG (PARI) for(n=1, 1e4, my(i=eulerphi(n)); if(omega(2*i)==1, print1(logint(i, 2), ", "))) CROSSREFS A000010, A003401, A094269. Sequence in context: A280128 A354703 A070096 * A024154 A117875 A084840 Adjacent sequences: A319818 A319819 A319820 * A319822 A319823 A319824 KEYWORD nonn AUTHOR Jianing Song, Sep 28 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 9 07:37 EST 2023. Contains 367689 sequences. (Running on oeis4.)