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A171825 Trajectory of 1 under repeated application of i -> A171823(i). 2
1, 101, 11110, 1011100, 11111100, 100010110, 1001101100, 1010101101, 1010100110, 1010101101, 1010100110, 1010101101, 1010100110, 1010101101, 1010100110, 1010101101, 1010100110, 1010101101, 1010100110, 1010101101 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Has become periodic with period {1010101101,1010100110}.

LINKS

Table of n, a(n) for n=1..20.

MAPLE

# Apply map to base-10 number

F:=proc(n) local t1, t2, t2b, n1, n1b, n0, n0b, t3, t4;

t1:=convert(n, base, 2);

t2:=nops(t1);

t2b:=convert(t2, base, 2);

n1:=add(t1[i], i=1..t2);

n1b:=convert(n1, base, 2);

n0:=t2-n1;

n0b:=convert(n0, base, 2);

t3:=[

seq(t2b[nops(t2b)+1-i], i=1..nops(t2b)),

seq(n0b[nops(n0b)+1-i], i=1..nops(n0b)),

seq(n1b[nops(n1b)+1-i], i=1..nops(n1b))

];

t4:="";

for i from 1 to nops(t3) do t4:=cat(t4, t3[i]); od:

parse(t4);

end;

# Apply map to binary number

G:=proc(n) local t2, t2b, n1, n1b, n0, n0b, t3, t4; global digsum;

t2:=length(n);

t2b:=convert(t2, base, 2);

n1:=digsum(n);

n1b:=convert(n1, base, 2);

n0:=t2-n1;

n0b:=convert(n0, base, 2);

t3:=[

seq(t2b[nops(t2b)+1-i], i=1..nops(t2b)),

seq(n0b[nops(n0b)+1-i], i=1..nops(n0b)),

seq(n1b[nops(n1b)+1-i], i=1..nops(n1b))

];

t4:="";

for i from 1 to nops(t3) do t4:=cat(t4, t3[i]); od:

parse(t4);

end;

# Then do 1, F(1), G(F(1)), G(%), G(%), ... .

CROSSREFS

Sequence in context: A138831 A267920 A300570 * A267937 A068160 A185893

Adjacent sequences:  A171822 A171823 A171824 * A171826 A171827 A171828

KEYWORD

nonn,base

AUTHOR

N. J. A. Sloane, Oct 16 2010

STATUS

approved

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Last modified June 21 03:24 EDT 2021. Contains 345354 sequences. (Running on oeis4.)