A383198 Number of positive integers with n digits in which adjacent digits differ by at most 3.

9, 54, 328, 2000, 12202, 74458, 454366, 2772710, 16920138, 103253214, 630091042, 3845059318, 23464039746, 143186649814, 873780342786, 5332145758694, 32538816680050, 198564450196598, 1211717109125762, 7394366670845606, 45123286657530514, 275359755529253142

Offset: 1

Author

Edwin Hermann, Apr 19 2025

Keywords

• nonn
• base
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (7,-4,-10,6).

Crossrefs

Cf. A235163, A383197, A383199, A383200, A383201, A383202.

Programs

Mathematica

LinearRecurrence[{7,-4,-10,6},{9, 54, 328, 2000},22] (* or *) Rest[CoefficientList[Series[(-x*(10*x^3-14*x^2-9*x+9)/(6*x^4-10*x^3-4*x^2+7*x-1)),{x,0,22}],x]] (* James C. McMahon, May 01 2025 *)

Formula

G.f.: -x*(10*x^3-14*x^2-9*x+9)/(6*x^4-10*x^3-4*x^2+7*x-1). - Alois P. Heinz, Apr 23 2025

Extensions

More terms from Alois P. Heinz, Apr 23 2025