OFFSET
1,2
COMMENTS
Conjecturally, the limit infimum is infinite. [Charles R Greathouse IV, Jun 28 2011]
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
EXAMPLE
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.
PROG
(PARI) diff(v)=vector(#v-1, i, v[i+1]-v[i])
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
CROSSREFS
KEYWORD
nonn
AUTHOR
Mick Purcell (mickpurcell(AT)gmail.com), Sep 25 2009
STATUS
approved