This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A166923 Digital root of prime(n)^2. 3
 4, 9, 7, 4, 4, 7, 1, 1, 7, 4, 7, 1, 7, 4, 4, 1, 7, 4, 7, 1, 1, 4, 4, 1, 4, 4, 7, 1, 1, 7, 1, 7, 4, 7, 7, 4, 7, 1, 7, 4, 1, 1, 4, 7, 1, 1, 7, 4, 4, 7, 1, 7, 4, 1, 7, 4, 1, 1, 4, 4, 7, 7, 1, 7, 4, 4, 4, 7, 7, 4, 4, 1, 4, 7, 1, 7, 4, 1, 7, 7, 7, 4, 1, 1, 4, 4, 1, 4, 4, 7, 1, 4, 1, 7, 7, 1, 7, 1, 1, 1, 4, 1, 7, 4, 7 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS MATHEMATICA Table[If[(m9=Mod[Prime[n]^2, 9])==0, 9, m9], {n, 200}] PROG (Python) from sympy import prime def A166923(n): ....return 1 + (prime(n)**2-1) % 9 # Chai Wah Wu, Sep 03 2014 CROSSREFS Cf. A010888, A038194. Sequence in context: A021909 A018880 A245670 * A021205 A296425 A306004 Adjacent sequences:  A166920 A166921 A166922 * A166924 A166925 A166926 KEYWORD base,nonn AUTHOR Zak Seidov, Oct 23 2009 EXTENSIONS Definition corrected by Chai Wah Wu, Sep 03 2014 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 18 18:10 EDT 2018. Contains 316323 sequences. (Running on oeis4.)