A383072 Number of n-digit positive integers where all pairs of consecutive digits have a difference of at least 4.

9, 36, 166, 722, 3224, 14236, 63172, 279728, 1239800, 5492776, 24339328, 107843024, 477848240, 2117296288, 9381580672, 41568964736, 184188672416, 816124473376, 3616179527008, 16022988545120, 70996522976672, 314579653288672, 1393876135246624, 6176148562918496

Offset: 1

Author

Edwin Hermann, Apr 15 2025

Keywords

• nonn
• base
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (3,8,-6,-6).

Crossrefs

Cf. A052268, A100062, A383070, A383071.

Programs

Mathematica

LinearRecurrence[{3,8,-6,-6},{9, 36, 166, 722},24] (* or *) Rest[CoefficientList[Series[x*(10*x^3+14*x^2-9*x-9)/(-6*x^4-6*x^3+8*x^2+3*x-1),{x,0,24}] ,x]] (* James C. McMahon, Apr 15 2025 *)

Formula

G.f.: x*(10*x^3+14*x^2-9*x-9)/(-6*x^4-6*x^3+8*x^2+3*x-1). - Alois P. Heinz, Apr 15 2025

Extensions

More terms from Alois P. Heinz, Apr 15 2025