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A114645 The numbers 2^n-1 written in groups of three digits, with leading zeros omitted. 5

%I #17 Dec 25 2022 14:02:40

%S 137,153,163,127,255,511,102,320,474,95,819,116,383,327,676,553,513,

%T 107,126,214,352,428,710,485,752,97,151,419,430,383,886,71,677,721,

%U 533,554,431,671,88,631,342,177,272,684,354,555,368,709,111,73,741,823,214,748

%N The numbers 2^n-1 written in groups of three digits, with leading zeros omitted.

%D Heard over coffee at the Computers in Scientific Discovery meeting in Ghent, Feb 02 2006.

%H Alois P. Heinz, <a href="/A114645/b114645.txt">Table of n, a(n) for n = 1..10000</a>

%e 1,3,7,15,31,63,...

%t FromDigits[#] & /@ Partition[ Flatten[ IntegerDigits[ Table[ 2^n - 1, {n, 31}]]], 3] (* _Robert G. Wilson v_, Jun 23 2014 *)

%o (Python)

%o from itertools import count, islice

%o def bgen(): yield from (d for n in count(1) for d in str((1 << n)-1))

%o def agen(): g = bgen(); yield from (int("".join(t)) for t in zip(g, g, g))

%o print(list(islice(agen(), 54))) # _Michael S. Branicky_, Dec 25 2022

%K nonn,base,dumb

%O 1,1

%A _N. J. A. Sloane_, Feb 18 2006

%E More terms from _Matthew Conroy_, Mar 12 2006

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Last modified April 24 02:42 EDT 2024. Contains 371917 sequences. (Running on oeis4.)