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 A124954 #12 Apr 30 2025 14:52:10
%S A124954 1,26,124,464,2032,8956,40498,185358,857352,3996572,18748294,88404078,
%T A124954 418649134,1989796094,9486867052,45353726944,217336589784,
%U A124954 1043666874012,5021108669734,24196986793782,116781703334762
%N A124954 Number of base 26 circular n-digit numbers with adjacent digits differing by 2 or less.
%C A124954 [Empirical] a(base,n)=a(base-1,n)+A005191(n+1) for base>=2.int(n/2)+1.
%C A124954 See A285280 for confirmation of linear recurrence and code to produce sequence. - _Ray Chandler_, Aug 12 2023.
%H A124954 Ray Chandler, <a href="/A124954/b124954.txt">Table of n, a(n) for n = 0..99</a>
%H A124954 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 A124954 <a href="/index/Rec#order_26">Index entries for linear recurrences with constant coefficients</a>, signature (26, -276, 1472, -3520, -1364, 26235, -38076, -55671, 171530, 18971, -349296, 102674, 410216, -187435, -296636, 150952, 132708, -65631, -35400, 15386, 5160, -1755, -340, 75, 6, -1).
%o A124954 (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 A124954 Cf. Row 26 of A285280.
%K A124954 nonn,base
%O A124954 0,2
%A A124954 _R. H. Hardin_, Dec 28 2006