%I #12 Dec 25 2022 14:02:25
%S 315,632,551,23,409,516,383,655,352,621,431,48,575,419,430,316,777,
%T 215,671,88,632,684,354,551,73,741,823,429,496,729,517,179,869,183,
%U 687,194,767,352,748,779,69,431,99,511,627,775,439,804,651,110,317,592,186,44
%N The numbers 4^n-1 written in groups of three digits, with leading zeros omitted.
%e 3, 15, 63, 255, 1023, 4095, 16383, ...
%t FromDigits[#] & /@ Partition[ Flatten@ IntegerDigits@ Table[4^n - 1, {n, 22}], 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 << 2*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
%Y Cf. A114645, A114804, A114808, A114827.
%K base,dumb,nonn
%O 1,1
%A _Jonathan Vos Post_, Feb 19 2006
%E a(4) and following changed by _Georg Fischer_, Dec 25 2022