A033557 2n - {largest prime < n}.

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, 33, 35, 31, 33, 33, 35, 37, 39, 41, 43, 39, 41, 43, 45, 43, 45, 45, 47, 49, 51, 49, 51, 53, 55, 57, 59, 55, 57, 59, 61, 63

Offset: 3

Author

N. J. A. Sloane

Keywords

• nonn

Crossrefs

A049711(n) + n.

Programs

Maple

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