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 A383070 #21 Apr 15 2025 22:05:44
%S A383070 9,64,463,3341,24125,174172,1257515,9079056,65549673,473259806,
%T A383070 3416873920,24669378486,178109665460,1285928315349,9284233050564,
%U A383070 67030939539430,483954553287069,3494088121160674,25226855944238001,182134576675940879,1314987650245129696
%N A383070 Number of n-digit positive integers where all pairs of consecutive digits have a difference of at least 2.
%H A383070 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (4,22,11,-14,-3).
%F A383070 G.f.: x*(3*x^4+18*x^3-9*x^2-28*x-9)/(-3*x^5-14*x^4+11*x^3+22*x^2+4*x-1). - _Alois P. Heinz_, Apr 15 2025
%t A383070 LinearRecurrence[{4,22,11,-14,-3},{9, 64, 463, 3341, 24125},21] (* or *) Rest[CoefficientList[Series[x*(3*x^4+18*x^3-9*x^2-28*x-9)/(-3*x^5-14*x^4+11*x^3+22*x^2+4*x-1),{x,0,21}] ,x]] (* _James C. McMahon_, Apr 15 2025 *)
%Y A383070 Cf. A052268, A100062, A383071, A383072.
%K A383070 nonn,base,easy
%O A383070 1,1
%A A383070 _Edwin Hermann_, Apr 15 2025
%E A383070 More terms from _Alois P. Heinz_, Apr 15 2025