A008866 - OEIS

%I #10 Mar 28 2014 02:16:32

%S 1,8,2,18,2,30,2,42,6,60,6,78,2,90,6,112,2,128,4,144,6,162,6,186,4,

%T 204,4,216,4,240,4,268,2,288,2,308,6,330,6,352,2,372,2,390,2,410,12,

%U 450,2,462,6,480,10,508,6,532

%N Prime(A052928(n+1)) + (-1)^n* prime(A109613(n)).

%D Problem #1210, Series Formation, by Charles W. Trigg, J. Rec. Math., 15 (1982), 221-222.

%p ithprime(2*ceil(n/2))+(-1)^n*ithprime(2*floor(n/2)+1);

%K nonn

%O 1,2

%A _N. J. A. Sloane_, _R. K. Guy_