This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A230959 #14 Nov 16 2023 14:40:46 %S A230959 987654321,987654320,987654310,987654210,987653210,987643210, %T A230959 987543210,986543210,976543210,876543210,98765432,987654320,98765430, %U A230959 98765420,98765320,98764320,98754320,98654320,97654320,87654320,98765431,98765430,987654310,98765410 %N A230959 If n is pandigital then 0 else (digits not occurring in decimal representation of n, arranged in decreasing order). %C A230959 a(0) > a(n) for n > 0; %C A230959 a(A171102(n)) = 0 by definition, but also a(A050289(n)) = 0. %H A230959 Reinhard Zumkeller, <a href="/A230959/b230959.txt">Table of n, a(n) for n = 0..10000</a> %t A230959 pd[n_]:=Module[{idn=Sort[IntegerDigits[n]]},If[idn==Range[0,9],0,FromDigits[ Reverse[ Complement[ Range[ 0,9],idn]]]]]; Table[pd[n],{n,0,30}] (* _Harvey P. Dale_, Nov 16 2023 *) %o A230959 (Haskell) %o A230959 import Data.List ((\\)) %o A230959 a230959 n = (if null cds then 0 else read cds) :: Integer %o A230959 where cds = "9876543210" \\ show n %o A230959 (Python) %o A230959 def A230959(n): return int(''.join(sorted(set('9876543210')-set(str(n)),reverse=True)) or 0) # _Chai Wah Wu_, Nov 23 2022 %Y A230959 Cf. A227362. %K A230959 nonn,base,look %O A230959 0,1 %A A230959 _Reinhard Zumkeller_, Nov 02 2013