A073435 - OEIS

%I #15 May 21 2020 21:18:11

%S 4,7,8,13,30,17,35,23,40,50,53,51,55,52,63,60,68,69,146,76,154,83,156,

%T 162,172,177,185,109,195,187,192,188,189,190,208,209,210,214,215,216,

%U 217,230,218,219,220,224,225,251,248,249,250,255,256,262,267,280,289

%N Smallest x such that remainder if x-th composite is divided by pi(x) equals n.

%H Robert Israel, <a href="/A073435/b073435.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = Min{x; Mod[A002808(x), A000720(x)]=n} = Min{x; A065861(x)=n}.

%e Remainder=4 appears first as Mod[c[13],Pi[13]]=Mod[22,6]=4, so a(4)=13.

%p N:= 100: m:= 1: V:= Vector(N): count:= 0:

%p for n from 6 while count < N do

%p   if not isprime(n) then

%p     m:= m+1;

%p     t:= n mod numtheory:-pi(m);

%p     if t > 0 and t <= N and V[t] = 0 then

%p       count:= count+1; V[t]:= m

%p     fi

%p   fi

%p od:

%p convert(V,list); # _Robert Israel_, May 21 2020

%Y Cf. A000720, A002808, A065861.

%K nonn,look

%O 1,1

%A _Labos Elemer_, Jul 31 2002