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%I #28 Sep 12 2019 04:48:11
%S 0,1,2,3,4,5,6,7,0,1,1,1,2,1,3,1,4,1,5,1,6,1,7,1,0,2,1,2,2,2,3,2,4,2,
%T 5,2,6,2,7,2,0,3,1,3,2,3,3,3,4,3,5,3,6,3,7,3,0,4,1,4,2,4,3,4,4,4,5,4,
%U 6,4,7,4,0,5,1,5,2,5,3,5,4,5,5,5,6,5,7,5,0,6,1
%N Triangle T(n,k): write n in base 8, reverse order of digits.
%H Robert Israel, <a href="/A031045/b031045.txt">Table of n, a(n) for n = 0..10003</a> (rows 0 to 3646, flattened)
%p seq(op(convert(n,base,8)),n=0..100); # _Robert Israel_, Jul 22 2019
%t Flatten[Table[Reverse[IntegerDigits[n,8]],{n,80}]] (* _Harvey P. Dale_, Aug 08 2011 *)
%o (PARI) A031045(n, k=-1)=/*k<0&&error("Flattened sequence not yet implemented.");*/n\8^k%8 \\ Assuming that columns are numbered starting with k=0 as in A030308, A030341, ... Note: The operation could be done using bitwise arithmetic, bitand(n>>(3*k),7), but this is not significantly faster in PARI. - _M. F. Hasler_, Jul 21 2013
%Y Cf. A030308, A030341, A030386, A031235, A030567, A031007, A031087, A031298 for the base-2 to base-10 analogs.
%K nonn,base,tabf,less
%O 0,3
%A _Clark Kimberling_
%E Initial 0 and better name by _Philippe Deléham_, Oct 20 2011
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