%I #15 May 13 2013 01:50:04
%S 1,2,3,4,7,12,29,84,355,2038,15723,156920,1959177,29788564,539206155,
%T 11406258536,277708694711,7683630307352,239005572292955,
%U 8281900782667178,317172995786425445
%N a(1)=1, a(n+1) = prime(a(n)+1) - a(n).
%e a(2) = prime(a(1)+1)-a(1) = 3-1 = 2;
%e a(3) = prime(a(2)+1)-a(2) = 5-2 = 3;
%e a(4) = prime(a(3)+1)-a(3) = 7-3 = 4;
%e a(5) = prime(a(4)+1)-a(4) = 11-4 = 7.
%Y Cf. A006508, A000040.
%K nonn
%O 1,2
%A _Gerasimov Sergey_, Feb 19 2012
%E a(19)-a(21) from _Charles R Greathouse IV_, Feb 20 2012