A031045 Triangle T(n,k): write n in base 8, reverse order of digits.

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, 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, 6, 4, 7, 4, 0, 5, 1, 5, 2, 5, 3, 5, 4, 5, 5, 5, 6, 5, 7, 5, 0, 6, 1

Offset: 0

Author

Clark Kimberling

Keywords

• nonn
• base
• tabf
• less

Links

• Robert Israel, Table of n, a(n) for n = 0..10003 (rows 0 to 3646, flattened)

Crossrefs

Cf. A030308, A030341, A030386, A031235, A030567, A031007, A031087, A031298 for the base-2 to base-10 analogs.

Programs

Maple

seq(op(convert(n,base,8)),n=0..100); # Robert Israel, Jul 22 2019

Mathematica

Flatten[Table[Reverse[IntegerDigits[n,8]],{n,80}]] (* Harvey P. Dale, Aug 08 2011 *)

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

Extensions

Initial 0 and better name by Philippe Deléham, Oct 20 2011