cp's OEIS Frontend

A022935 a(n) = a(n-1) + c(n-1) for n >= 2, a( ) increasing, given a(1)=3, where c( ) is complement of a( ).

%I A022935 #22 Sep 16 2015 02:01:47
%S A022935 3,4,6,11,18,26,35,45,57,70,84,99,115,132,151,171,192,214,237,261,286,
%T A022935 313,341,370,400,431,463,496,530,566,603,641,680,720,761,803,846,890,
%U A022935 936,983,1031,1080,1130,1181,1233,1286,1340,1395,1451,1509
%N A022935 a(n) = a(n-1) + c(n-1) for n >= 2, a( ) increasing, given a(1)=3, where c( ) is complement of a( ).
%C A022935 Complement means that c(i) is the i-th member of the sorted list of integers >=1 that are not in the set {a(1),...,a(i-1)}. - _R. J. Mathar_, Aug 06 2015
%H A022935 Vincenzo Librandi, <a href="/A022935/b022935.txt">Table of n, a(n) for n = 1..1000</a>
%t A022935 mex := First[Complement[Range[1, Max[#1] + 1], #1]] &;
%t A022935 a[1] = 3; c[1] = 1; c[2] = 2;
%t A022935 a[n_] := a[n] = a[n - 1] + c[n - 1];
%t A022935 c[n_] := c[n] = mex[Flatten[Table[{a[i], c[i]}, {i, 1, n - 1}]]];
%t A022935 Table[a[n], {n, 80}]  (* A022935 *)
%t A022935 Table[c[n], {n, 80}]
%t A022935 (* _Clark Kimberling_, May 15 2012 *)
%K A022935 nonn
%O A022935 1,1
%A A022935 _Clark Kimberling_