%I #5 May 13 2013 01:54:10

%S 1,2,3,1,6,2,12,4,17,7,8,34,14,16,68,28,32,87,49,56,64,174,98,112,128,

%T 348,196,224,256,353,343,392,448,512,706,686,784,896,1024,1412,1372,

%U 1568,1792,2048,423,2401,2744,3136,3584,4096,846,4802,5488,6272,7168,8192,1692,9604,10976,12544,14336,2961,13423,3384,19208

%N First differences of A003591.

%C Conjecturally, the limit infimum is infinite. [_Charles R Greathouse IV_, Jun 28 2011]

%H Charles R Greathouse IV, <a href="/A165742/b165742.txt">Table of n, a(n) for n = 1..10000</a>

%e For n = 5, the 5th number of the form 2^i*7^j with i, j >= 0 is 8, and the 6th number of the form 2^i*7^j with i, j >= 0 is 14, so the difference is 14 - 8 = 6.

%o (PARI) diff(v)=vector(#v-1,i,v[i+1]-v[i])

%o list(lim)=my(v=List(),N);for(n=0,log(lim)\log(7),N=7^n;while(N<=lim,listput(v,N);N<<=1));diff(vecsort(Vec(v))) \\ _Charles R Greathouse IV_, Jun 28 2011

%K nonn

%O 1,2

%A Mick Purcell (mickpurcell(AT)gmail.com), Sep 25 2009