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!)
 A214720 Least m>0 such that n^2-m and n-m are relatively prime. 2
 2, 1, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 7, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 7, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Clark Kimberling, Table of n, a(n) for n = 1..1000 EXAMPLE a(12) = 5 because of the following: gcd(144-1,11) > 1, gcd(144-2,10) > 1 , gcd(144-3,9) > 1, gcd(144-4,8) >1, gcd(144-5,7) = 1. MAPLE A214720 := proc(n)     for m from 1 do         if igcd(n^2-m, n-m) =1  then             return m;         end if;     end do: end proc: # R. J. Mathar, Mar 30 2014 MATHEMATICA Table[m = 1; While[GCD[5^n - m, n - m] != 1, m++]; m, {n, 1, 140}] CROSSREFS Cf. A214716, A053669. Sequence in context: A250099 A241949 A288126 * A035368 A249686 A107853 Adjacent sequences:  A214717 A214718 A214719 * A214721 A214722 A214723 KEYWORD nonn,easy AUTHOR Clark Kimberling, Jul 27 2012 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 April 12 11:36 EDT 2021. Contains 342920 sequences. (Running on oeis4.)