A023791 - OEIS

%I #12 Feb 12 2022 18:50:15

%S 0,1,2,3,4,5,6,7,8,9,18,19,27,28,29,36,37,38,39,45,46,47,48,49,54,55,

%T 56,57,58,59,63,64,65,66,67,68,69,72,73,74,75,76,77,78,79,171,252,261,

%U 262,333,342,343,351,352,353,414,423,424,432,433,434,441,442

%N Katadromes: digits in base 9 are in strict descending order.

%H Sean A. Irvine, <a href="/A023791/b023791.txt">Table of n, a(n) for n = 1..511</a>

%t ktdQ[n_]:=AllTrue[Differences[IntegerDigits[n,9]],#<0&]; Select[Range[ 0,500],ktdQ] (* _Harvey P. Dale_, Feb 12 2022 *)

%K nonn,base,fini,full,easy

%O 1,3

%A _Olivier Gérard_