%I A161811
%S A161811 4,5,4,3,2,3,4,3,2,3,4,3,2,3,3,2,2,2,3,4,3,2,2,2,3,3,2,3,4,3,2,3,3,2,2,
%T A161811 2,3,3,2,2,2,3,4,3,2,2,2,3,3,2,3,4,3,2,2,2,3,3,2,3,3,2,2,2,3,3,2,2,2,2,
%U A161811 2,3,3,2,3,4,3,2,3,4,3,2,3,3,2,2,2,2,2,2,2,2,2,2,2,3,3,2,3,3,2,2,2,3,4
%N A161811 Difference between nonprime(n+2) and nonprime(n).
%C A161811 "nonprime(n)" is used for "n-th nonprime". Here the nonprimes start at 
               0 (see A141468), so nonprime(1) to nonprime(15) are 0, 1, 4, 6, 8, 
               9, 10, 12, 14, 15, 16, 18, 20, 21, 22.
%F A161811 a(n) = A141468(n+2)-A141468(n).
%e A161811 nonprime(1+2)-nonprime(1) = 4-0; so a(1) = 4.
%e A161811 nonprime(5+2)-nonprime(5) = 10-8; so a(5) = 2.
%e A161811 nonprime(11+2)-nonprime(11) = 20-16; so a(11) = 4.
%Y A161811 Cf. A031131, A141468.
%Y A161811 Sequence in context: A120867 A011427 A071413 this_sequence A016717 A031349 
               A036444
%Y A161811 Adjacent sequences: A161808 A161809 A161810 this_sequence A161812 A161813 
               A161814
%K A161811 nonn
%O A161811 1,1
%A A161811 Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Jun 20 2009
%E A161811 Edited, corrected (a(11)=2 replaced by 4) and extended by Klaus Brockhaus 
               (klaus-brockhaus(AT)t-online.de), Jun 24 2009