A065130 - OEIS

%I #4 Mar 30 2012 17:33:48

%S 0,0,1,2,3,5,7,9,11,14,17,20,23,26,30,34,38,42,46,50,54,59,64,69,74,

%T 79,84,89,94,100,106,112,118,124,130,136,142,148,155,162,169,176,183,

%U 190,197,204,211,218,226,234,242,250,258,266,274,282

%N a(n) = A005228(n) - A000217(n).

%t a = {1}; d = 2; k = 1; Do[ While[ Position[a, d] != {}, d++ ]; k = k + d; d++; a = Append[a, k], {n, 1, 55} ]; b = Table[ n(n + 1)/2, {n, 1, 56} ]; a-b

%K easy,nonn

%O 1,4

%A _Robert G. Wilson v_, Nov 14 2001

%E Corrected definition by _Omar E. Pol_, Dec 24 2008