OFFSET
1,2
LINKS
Muniru A Asiru, Table of n, a(n) for n = 1..400
FORMULA
a(n+1)/a(n) is in {16, 64, 1024}, so 16^n <= a(n+1) < 1024^n. Asymptotically, the exponent should be 100; I can prove that 99^n << a(n) << 101^n. [Charles R Greathouse IV, Jan 19 2012]
MAPLE
select(x-> "1"=""||x[1], [4^n$n=0..60])[]; # Alois P. Heinz, Oct 22 2018
PROG
(GAP) Filtered(List([0..40], n->4^n), i->ListOfDigits(i)[1]=1); # Muniru A Asiru, Oct 22 2018
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Amarnath Murthy, Feb 09 2002
EXTENSIONS
a(16) inserted by Muniru A Asiru, Oct 22 2018
STATUS
approved