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 A383307 #16 Apr 27 2025 15:03:32
%S A383307 1,0,30,631,8318,84939,762621,6836799,66714966,698183347,7345264685,
%T A383307 74862560359,738289921745,7152117119827,69258386123495,
%U A383307 678852874461343,6757612542040310,67956663939884115,684414144298352061,6858156111567293583,68247431544857431593,675967074881581484903
%N A383307 a(n) is number of n-digit nonnegative integers whose difference between the largest and smallest digits is equal to the mode of its digits.
%H A383307 Wikipedia, <a href="https://en.wikipedia.org/wiki/Mode_(statistics)">Mode (statistics)</a>
%F A383307 Conjecture: lim_{n->oo} a(n+1)/a(n) = 10. - _Stefano Spezia_, Apr 26 2025
%t A383307 a[n_]:=Module[{c=KroneckerDelta[n,1]}, For[k=10^(n-1), k<=10^n, k++, If[{Max[d=IntegerDigits[k]]-Min[d]}==Commonest[d], c++]]; c]; Array[a,6]
%Y A383307 Cf. A037904, A054054, A054055, A115353, A383306.
%K A383307 nonn,base
%O A383307 1,3
%A A383307 _Stefano Spezia_, Apr 22 2025
%E A383307 More terms from _Bert Dobbelaere_, Apr 25 2025