OFFSET
1,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = reverse(4*a(n-1)) where a(1) = 1
Conjecture: a(n)^(1/n) tends to 10. - Vaclav Kotesovec, Jan 03 2020
EXAMPLE
a(4) = reverse(4*a(3)) = reverse(4*reverse(4*a(2))) = reverse(4*reverse(4*reverse(4*a(1)))) = reverse(4*reverse(4*4)) = reverse(4*61) = reverse(244) = 442
MAPLE
a:= proc(n) option remember; `if`(n=1, 1,
(s-> parse(cat(s[-i]$i=1..length(s))))(""||(4*a(n-1))))
end:
seq(a(n), n=1..30); # Alois P. Heinz, Apr 09 2015
MATHEMATICA
NestList[IntegerReverse[4#]&, 1, 20] (* Requires Mathematica version 11 or later *) (* Harvey P. Dale, Dec 09 2017 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Rachit Agrawal (rachit_agrawal(AT)daiict.ac.in), Oct 30 2007
EXTENSIONS
More terms from Alois P. Heinz, Apr 09 2015
STATUS
approved