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 A125355 #9 Apr 30 2025 15:13:46
%S A125355 1,18,142,918,6902,52818,413974,3289290,26413814,213785910,1740901972,
%T A125355 14244084664,116982000962,963573445450,7955405806616,65801903210688,
%U A125355 545060017403430,4520080784608610,37517875619404780,311628272467347236
%N A125355 Number of base 18 circular n-digit numbers with adjacent digits differing by 4 or less.
%C A125355 [Empirical] a(base,n)=a(base-1,n)+A025014(n+1) for base>=4.int(n/2)+1
%H A125355 OEIS Wiki, <a href="/wiki/Number_of_base_k_circular_n-digit_numbers_with_adjacent_digits_differing_by_d_or_less">Number of base k circular n-digit numbers with adjacent digits differing by d or less</a>
%o A125355 (S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>4)+($[(i+1)mod N]`-$[i]`>4))
%K A125355 nonn,base
%O A125355 0,2
%A A125355 _R. H. Hardin_, Dec 28 2006