login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Numbers k such that A001223(k) < A000005(k).
4

%I #9 Feb 03 2019 12:22:30

%S 10,12,20,26,28,33,35,36,40,44,45,48,49,50,52,54,56,57,60,63,64,69,70,

%T 72,75,78,81,84,88,90,96,98,100,102,104,105,108,110,112,116,117,120,

%U 126,130,132,136,140,142,144,147,148,152,153,156,160,165

%N Numbers k such that A001223(k) < A000005(k).

%H Nathaniel Johnston, <a href="/A162189/b162189.txt">Table of n, a(n) for n = 1..10000</a>

%H Omar E. Pol, <a href="http://www.polprimos.com/imagenespub/polprdipi.jpg">Illustration: Divisors and pi(x)</a>

%p p2:=2:for n from 1 to 200 do p1:=p2:p2:=ithprime(n+1):if(p2-p1<tau(n))then print(n);fi:od: # _Nathaniel Johnston_, Apr 15 2011

%Y Cf. A000005, A001223, A068526, A161911, A161912, A161913, A162188.

%K easy,nonn

%O 1,1

%A _Omar E. Pol_, Jul 04 2009

%E a(30)-a(56) from _Nathaniel Johnston_, Apr 15 2011