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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A063828 Smallest m associated with n-th Pillai prime (A063980). 3

%I #28 Nov 02 2023 14:18:18

%S 14,18,15,8,18,9,23,13,86,16,16,50,102,61,64,210,97,31,9,93,40,45,63,

%T 220,91,122,35,85,198,93,128,316,366,74,300,151,290,15,400,282,22,188,

%U 167,191,360,426,274,271,456,278,229,324,135,498,189

%N Smallest m associated with n-th Pillai prime (A063980).

%H Charles R Greathouse IV, <a href="/A063828/b063828.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from T. D. Noe)

%H G. E. Hardy and M. V. Subbarao, <a href="https://www.jstor.org/stable/2695445">A modified problem of Pillai and some related questions</a>, Amer. Math. Monthly 109 (2002), no. 6, 554-559.

%e 14! + 1 == 0 (mod 23), while 23 != 1 (mod 14), where 23=A063980(1) so a(1)=14.

%t nn=1000; fact=1+Rest[FoldList[Times,1,Range[nn]]]; t={}; Do[p=Prime[i]; m=2; While[m<p && !(Mod[p,m]!=1 && Mod[fact[[m]],p]==0), m++]; If[m<p, AppendTo[t,m]], {i,2,PrimePi[nn]}]; t (* _T. D. Noe_, Apr 22 2011 *)

%o (PARI) first(p)=my(t=Mod(5040, p)); for(m=8, p, t*=m; if(t==-1 && p%m!=1, return(m))); 0

%o Pillai(p)=my(t=Mod(5040, p)); for(m=8, p-2, t*=m; if(t==-1 && p%m!=1, return(1))); 0

%o apply(first, select(Pillai, primes(300))) \\ _Charles R Greathouse IV_, Feb 10 2013

%Y Cf. A063980, A211411.

%K nonn

%O 1,1

%A _N. J. A. Sloane_, Sep 23 2001

%E More terms from _Vladeta Jovovic_, Sep 27 2001

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 19 15:03 EDT 2024. Contains 371794 sequences. (Running on oeis4.)