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 A124894 #12 Apr 30 2025 14:46:41
%S A124894 1,16,74,274,1182,5146,22988,104008,475702,2193322,10178844,47489128,
%T A124894 222537384,1046705104,4938809502,23367231454,110821701894,
%U A124894 526680449962,2507653172738,11959006821214,57115337351332,273132653565388
%N A124894 Number of base 16 circular n-digit numbers with adjacent digits differing by 2 or less.
%C A124894 [Empirical] a(base,n)=a(base-1,n)+A005191(n+1) for base>=2.int(n/2)+1.
%C A124894 See A285280 for confirmation of linear recurrence and code to produce sequence. - _Ray Chandler_, Aug 12 2023.
%H A124894 Ray Chandler, <a href="/A124894/b124894.txt">Table of n, a(n) for n = 0..99</a>
%H A124894 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 A124894 <a href="/index/Rec#order_16">Index entries for linear recurrences with constant coefficients</a>, signature (16, -91, 182, 155, -956, 362, 1692, -1027, -1400, 846, 556, -275, -92, 30, 4, -1).
%o A124894 (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 A124894 Cf. Row 16 of A285280.
%K A124894 nonn,base
%O A124894 0,2
%A A124894 _R. H. Hardin_, Dec 28 2006