cp's OEIS Frontend

A085345 Least number x such that number of primes between phi(x) and x equals n.

%I A085345 #8 Aug 23 2018 15:52:46
%S A085345 2,6,12,18,24,30,50,42,48,66,60,78,96,84,90,130,108,176,114,132,156,
%T A085345 182,150,168,186,180,216,198,228,429,210,258,308,240,276,282,270,306,
%U A085345 294,300,354,366,336,330,384,378,396,360,432,438,622,444,390,490,474,498
%N A085345 Least number x such that number of primes between phi(x) and x equals n.
%H A085345 Robert Israel, <a href="/A085345/b085345.txt">Table of n, a(n) for n = 1..10000</a>
%F A085345 a(n)=Min{x; A085342(x)=n}
%p A085345 N:= 200: # for a(1)..a(N)
%p A085345 V:= Vector(N):
%p A085345 count:= 0:
%p A085345 for x from 1 while count < N do
%p A085345   v:= numtheory:-pi(x) - numtheory:-pi(numtheory:-phi(x));
%p A085345   if v >= 1 and v <= N and V[v] = 0 then
%p A085345     V[v]:= x; count:= count+1;
%p A085345   fi
%p A085345 od:
%p A085345 convert(V,list); # _Robert Israel_, Aug 23 2018
%Y A085345 Cf. A000720, A000010, A000203, A070803, A070804, A085341-A085347.
%K A085345 nonn
%O A085345 1,1
%A A085345 _Labos Elemer_, Jul 10 2003