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 A125320 #12 Apr 30 2025 15:01:20
%S A125320 1,10,58,286,1618,9330,54994,328058,1973026,11928418,72360138,
%T A125320 439900746,2677993234,16317209282,99477496666,606677367546,
%U A125320 3700738695234,22577766952946,137756725752298,840561549454570
%N A125320 Number of base 10 circular n-digit numbers with adjacent digits differing by 3 or less.
%C A125320 [Empirical] a(base,n)=a(base-1,n)+A025012(n+1) for base>=3.int(n/2)+1
%H A125320 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>
%F A125320 G.f.: (1 - 21*x^2 - 56*x^3 + 192*x^4 + 112*x^5 - 260*x^6 - 48*x^7 + 84*x^8) / ((1 + x)*(1 - 4*x + 2*x^3)*(1 - 7*x + 4*x^2 + 10*x^3 - 6*x^4)) (conjectured). - _Colin Barker_, Jun 01 2017
%o A125320 (S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>3)+($[(i+1)mod N]`-$[i]`>3))
%K A125320 nonn,base
%O A125320 0,2
%A A125320 _R. H. Hardin_, Dec 28 2006