A033557 - OEIS

%I #4 Mar 30 2012 16:47:23

%S 4,5,7,7,9,9,11,13,15,13,15,15,17,19,21,19,21,21,23,25,27,25,27,29,31,

%T 33,35,31,33,33,35,37,39,41,43,39,41,43,45,43,45,45,47,49,51,49,51,53,

%U 55,57,59,55,57,59,61,63

%N 2n - {largest prime < n}.

%p f := n->2*n-prevprime(n); [ seq(f(i),i=3..60) ];

%Y A049711(n) + n.

%K nonn

%O 3,1

%A _N. J. A. Sloane_.