A118027 - OEIS

A118027

a(0) = 0, a(n) = a(n-1) + (smallest integer which is >= n and is missing from the earlier terms of the sequence).

%I #12 Sep 16 2017 19:57:28

%S 0,1,3,7,11,16,22,30,38,47,57,69,81,94,108,123,140,157,175,194,214,

%T 235,258,281,305,330,356,383,411,440,471,502,534,567,601,636,672,709,

%U 748,787,827,868,910,953,997,1042,1088,1136,1184,1233,1283,1334,1386,1439

%N a(0) = 0, a(n) = a(n-1) + (smallest integer which is >= n and is missing from the earlier terms of the sequence).

%H Michael De Vlieger, <a href="/A118027/b118027.txt">Table of n, a(n) for n = 0..10000</a>

%t a = {1}; Do[k = i; While[MemberQ[a, k], k++]; AppendTo[a, a[[i - 1]] + k], {i, 2, 53}]; {0}~Join~a (* _Michael De Vlieger_, Sep 16 2017 *)

%Y Cf. A118026, A118028, A118029, A118030, A094589.

%K easy,nonn

%O 0,3

%A _Leroy Quet_, Apr 10 2006

%E More terms from Wendy Kalasky (wkk107(AT)psu.edu), Apr 26 2006