OFFSET
0,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
Nick Hobson, Python program for this sequence
FORMULA
a(n+1) = A004093(a(n)). - Reinhard Zumkeller, Feb 09 2012
Conjecture: a(n)^(1/n) tends to sqrt(10). - Vaclav Kotesovec, Jan 03 2020
MATHEMATICA
NestList[ FromDigits[ Reverse[ IntegerDigits[ 2# ] ] ] &, 1, 27 ]
NestList[IntegerReverse[2#]&, 1, 30] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 18 2017 *)
PROG
(Haskell)
a036447 n = a036447_list !! n
a036447_list = iterate a004093 1 -- Reinhard Zumkeller, Feb 09 2012
CROSSREFS
The following are parallel families: A000079 (2^n), A004094 (2^n reversed), A028909 (2^n sorted up), A028910 (2^n sorted down), A036447 (double and reverse), A057615 (double and sort up), A263451 (double and sort down); A000244 (3^n), A004167 (3^n reversed), A321540 (3^n sorted up), A321539 (3^n sorted down), A163632 (triple and reverse), A321542 (triple and sort up), A321541 (triple and sort down).
KEYWORD
nonn,base,easy,nice
AUTHOR
EXTENSIONS
More terms from Larry Reeves (larryr(AT)acm.org), Mar 31 2000
STATUS
approved