A056983 - OEIS

%I #10 Mar 26 2024 05:54:11

%S 3,11,17,23,29,37,41,43,53,67,73,79,97,101,107,109,127,131,139,149,

%T 151,157,163,173,191,199,211,229,239,251,257,263,271,281,283,293,307,

%U 311,313,331,337,347,349,359,373,379,383,389,397,409,421,433,443,449

%N Primes p which divide Sum_{i=1..m} i! for some m (see A125138).

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Smarandache-WagstaffFunction.html">Smarandache-Wagstaff Function.</a>

%p isA056983 := proc(p)

%p     local idxp ;

%p     if not isprime(p) then

%p         return false ;

%p     end if;

%p     idxp := numtheory[pi](p) ;

%p     if A125138(idxp) > 0 then

%p         true ;

%p     else

%p         false ;

%p     end if;

%p end proc:

%p A056983 := proc(n)

%p     option remember ;

%p     local p;

%p     if n = 1 then

%p         3;

%p     else

%p         p := procname(n-1) ;

%p         while true do

%p             p := nextprime(p) ;

%p             if isA056983(p) then

%p                 return p;

%p             end if;

%p         end do:

%p     end if;

%p end proc:

%p seq(A056983(n),n=1..70) ; # _R. J. Mathar_, Mar 26 2024

%Y Cf. A007489, A056984, A056985, A125138.

%K nonn

%O 1,1

%A _Eric W. Weisstein_