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 A365258 #23 Nov 23 2023 11:25:52 %S A365258 2983,3892,4197,4917,5298,5928,7194,7398,7914,7938,8139,8295,8329, %T A365258 8397,8925,8937,9238,9318 %N A365258 The four digits of a(n), their three successive absolute first differences and their two successive absolute second differences are all distinct. %C A365258 The digit 0 is never present in a(n) and never appears as a first or a second difference (as this would duplicate in both cases one of the 8 remaining digits involved). %C A365258 The sequence ends with a(18) = 9318. %e A365258 2983 is a term since its three successive absolute first differences 7 (= 2 - 9), 1 (= 9 - 8), 5 (= 8 - 3) and the successive absolute second differences 6 (= 7 - 1) and 4 (= 1 - 5), are nine distinct digits. %e A365258 2 9 8 3 %e A365258 7 1 5 %e A365258 6 4 %t A365258 Select[Range[1000,9999],Sort@Join[IntegerDigits@#, s=Abs@Differences@IntegerDigits@#, Abs@Differences@s]==Range@9&] %Y A365258 Cf. A365257, A100787, A040114, A270263. %K A365258 base,nonn,fini,full %O A365258 1,1 %A A365258 _Eric Angelini_ and _Giorgos Kalogeropoulos_, Aug 29 2023