%I
%S 1,2,3,3,4,6,5,7,8,6,9,12,7,17,13,8,15,18,9,21,19,6,30,11,24,19,23,18,
%T 30,27,22,18,42,11,30,42,9,39,36,30,19,56,6,48,57,13,44,46,17,45,69,
%U 13,41,49,56,27,85,18,30,84,26,64,26,64,47,54,45,94,17,36,85,60,23,79,98
%N First differences of A000960, divided by 2.
%t del[lst_, k_] := lst[[ Select[ Range[ Length[ lst]], Mod[ #, k] != 0 &]]]; For[ k = 2; s = Range[10000], k <= Length[s], k++, s = del[s, k]]; (Drop[s, 1]  Drop[s, 1])/2
%Y Cf. A000960, A056526.
%K nonn,easy
%O 1,2
%A _N. J. A. Sloane_, Nov 15 2004
%E More terms from _Robert G. Wilson v_, Nov 15 2004
