A235401 - OEIS

A235401

a(1) = 2 and a(n+1) = smallest k > a(n) such that for every 1<=j<=n the value k mod a(j) is not in the sequence.

%I #17 Apr 07 2014 05:22:45

%S 2,3,4,9,16,24,37,45,60,72,108,133,141,216,252,433,501,529,648,673,

%T 792,861,1069,1105,1153,1249,1296,1573,1581,2005,2412,2689,2881,2952,

%U 3553,3949,4129,4273,4317,4609,4705,5328,5397,5605,5901,6300,6325,6480,7056,7201

%N a(1) = 2 and a(n+1) = smallest k > a(n) such that for every 1<=j<=n the value k mod a(j) is not in the sequence.

%C Note that setting a(1) = 1, instead of a(1) = 2, we obtain the sequence 1, 2, 4, 8,..., i.e., the powers of 2. - _Giovanni Resta_, Apr 07 2014

%H Giovanni Resta, <a href="/A235401/b235401.txt">Table of n, a(n) for n = 1..1000</a>

%t s = {2}; While[(n = Length@s) < 50, z = 1 + Last@s; While[ Catch[ Do[ If[Mod[z - s[[i]], s[[j]]] == 0, Throw@True], {j, 2, n}, {i, j-1}]; False], z++]; AppendTo[s, z]]; s (* _Giovanni Resta_, Jan 10 2014 *)

%K nonn

%O 1,1

%A _Paul Olaves Foss_, Jan 09 2014

%E a(36)-a(50) from _Giovanni Resta_, Jan 10 2014