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Powers of 2 written in base 9.
(Formerly M1138 N0434)
5

%I M1138 N0434 #37 Feb 01 2022 01:32:53

%S 1,2,4,8,17,35,71,152,314,628,1357,2725,5551,12212,24424,48848,108807,

%T 218715,438531,878162,1867334,3845668,7802447,16705005,34511011,

%U 70122022,150244044,310488088,621087187,1342185385,2684381781,5478773672,12068657454,24148426018

%N Powers of 2 written in base 9.

%D Archimedeans Problems Drive, Eureka, 14 (1951), 13.

%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H Alois P. Heinz, <a href="/A001357/b001357.txt">Table of n, a(n) for n = 0..1000</a> (first 301 terms from T. D. Noe)

%p b:= proc(n) local m; m:= n; "";

%p while m>0 do irem(m, 9, 'm'), % od;

%p parse(cat(%))

%p end:

%p a:= n-> b(2^n):

%p seq(a(n), n=0..42); # _Alois P. Heinz_, Aug 21 2019

%t Table[FromDigits[IntegerDigits[2^n, 9]], {n, 0, 30}] (* _T. D. Noe_, Jun 28 2012 *)

%o (PARI) {for(ixp=0, 34,

%o casi = 2^ixp; cvst=0;

%o while(casi != 0,

%o cvd = casi%9; cvst=10*cvst + cvd + 1; casi = (casi - cvd) / 9 );

%o while(cvst !=0,

%o ptch = cvst%10; print1(ptch-1); cvst = (cvst - ptch) / 10 );

%o print1(", "))} /* _Douglas Latimer_, Apr 23 2012 */

%K easy,base,nonn

%O 0,2

%A _N. J. A. Sloane_

%E More terms from _Douglas Latimer_, Apr 16 2012