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 A124955 #12 Apr 30 2025 14:52:28
%S A124955 1,27,129,483,2117,9337,42249,193493,895517,4176897,19605239,92495573,
%T A124955 438260309,2084105193,9941672807,47552376493,227988078573,
%U A124955 1095365516417,5272454219583,25420784798597,122748340134507
%N A124955 Number of base 27 circular n-digit numbers with adjacent digits differing by 2 or less.
%C A124955 [Empirical] a(base,n)=a(base-1,n)+A005191(n+1) for base>=2.int(n/2)+1.
%C A124955 See A285280 for confirmation of linear recurrence and code to produce sequence. - _Ray Chandler_, Aug 12 2023.
%H A124955 Ray Chandler, <a href="/A124955/b124955.txt">Table of n, a(n) for n = 0..99</a>
%H A124955 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 A124955 <a href="/index/Rec#order_26">Index entries for linear recurrences with constant coefficients</a>, signature (27, -300, 1700, -4531, 23, 31338, -57950, -52991, 249983, -50491, -511207, 308325, 614063, -492688, -462734, 414962, 221420, -202415, -65687, 56707, 11333, -8470, -1000, 570, 36, -12).
%o A124955 (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 A124955 Cf. Row 27 of A285280.
%K A124955 nonn,base
%O A124955 0,2
%A A124955 _R. H. Hardin_, Dec 28 2006