

A334025


a(0)=0, a(1)=1; and a(n) = {2*a(n2), 2*a(n1)}, where {x,y} is the concatenation of x and y.


0



0, 1, 2, 24, 448, 48896, 89697792, 97792179395584, 179395584195584358791168, 195584358791168358791168391168717582336, 358791168391168717582336391168717582336717582336782337435164672
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,3


COMMENTS

This sequence, due to the process of concatenating one number with another, bears similarities to A131293 and other familiar sequences. However, unlike A131293, this sequence increases at a faster rate. It happens due to the multiplier applied to the existing terms, which increases the number of digits present in the successive term drastically (see a(7) and a(8)). a(11) is too large to include here and has 102 digits.


LINKS



EXAMPLE

a(2) = {2*a(22), 2*a(21)} = {2*0, 2*1} = 02 = 2.
a(5) = {2*a(52), 2*a(51)} = {2*24, 2*448} = 48896.


MATHEMATICA

a[0] = 0; a[1] = 1; a[n_] := a[n] = FromDigits @ Join[IntegerDigits[2*a[n  2]], IntegerDigits[2*a[n  1]]]; Array[a, 11, 0] (* Amiram Eldar, Apr 18 2020 *)


CROSSREFS



KEYWORD

nonn,base


AUTHOR



STATUS

approved



