%I #18 Aug 07 2024 10:35:25
%S 0,1,2,3,4,5,6,7,8,9,10,19,28,37,46,55,64,73,18,19,20,29,38,47,56,65,
%T 74,27,28,29,30,39,48,57,66,75,36,37,38,39,40,49,58,67,76,45,46,47,48,
%U 49,50,59,68,77,54,55,56,57,58,59,60,69,78,63,64,65,66,67,68,69
%N Write n in 9-ary, sort digits into decreasing order.
%H Seiichi Manyama, <a href="/A319726/b319726.txt">Table of n, a(n) for n = 0..6560</a>
%F n <= a(n) < 9n. - _Charles R Greathouse IV_, Aug 07 2024
%t Table[FromDigits[Reverse[Sort[IntegerDigits[n,9]]],9],{n,0,70}] (* _Harvey P. Dale_, Oct 26 2022 *)
%o (Ruby)
%o def A(k, n)
%o (0..n).map{|i| i.to_s(k).split('').sort.reverse.join.to_i(k)}
%o end
%o p A(9, 100)
%o (PARI) a(n) = fromdigits(vecsort(digits(n, 9), , 4), 9); \\ _Michel Marcus_, Sep 26 2018
%Y b-ary: A073138 (b=2), A319651 (b=3), A319720 (b=4), A319722 (b=5), A319723 (b=6), A319724 (b=7), A319725 (b=8), this sequence (b=9), A004186 (b=10).
%Y Cf. A165110, A319657.
%K nonn,base,look,easy
%O 0,3
%A _Seiichi Manyama_, Sep 26 2018