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 A124858 #12 Apr 30 2025 14:36:31
%S A124858 1,12,54,198,842,3622,15984,71468,323042,1472022,6751064,31123148,
%T A124858 144092684,669468708,3119587196,14572658668,68216250402,319893194558,
%U A124858 1502357897232,7064711394284,33257109397452,156701323391972
%N A124858 Number of base 12 circular n-digit numbers with adjacent digits differing by 2 or less.
%C A124858 [Empirical] a(base,n)=a(base-1,n)+A005191(n+1) for base>=2.int(n/2)+1.
%C A124858 See A285280 for confirmation of linear recurrence and code to produce sequence. - _Ray Chandler_, Aug 12 2023.
%H A124858 Ray Chandler, <a href="/A124858/b124858.txt">Table of n, a(n) for n = 0..99</a>
%H A124858 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>
%H A124858 <a href="/index/Rec#order_11">Index entries for linear recurrences with constant coefficients</a>, signature (12, -45, 30, 134, -160, -141, 170, 59, -60, -9, 6).
%o A124858 (S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>2)+($[(i+1)mod N]`-$[i]`>2))
%Y A124858 Cf. Row 12 of A285280.
%K A124858 nonn,base
%O A124858 0,2
%A A124858 _R. H. Hardin_, Dec 28 2006