A383197 Number of positive integers with n digits in which adjacent digits differ by at most 2.

9, 41, 188, 867, 4010, 18574, 86096, 399225, 1851529, 8587802, 39833891, 184770640, 857073208, 3975623218, 18441391129, 85542653145, 396800342804, 1840608838251, 8537899488042, 39604141848678, 183708898915088, 852157340908409, 3952841397780937, 18335763176322738

Offset

1,1

Links

Table of n, a(n) for n=1..24.

Index entries for linear recurrences with constant coefficients, signature (7,-11,0,1).

Formula

G.f.: -x*(2*x^3-22*x+9)/(x^4-11*x^2+7*x-1). - Alois P. Heinz, Apr 21 2025

Crossrefs

Cf. A235163, A383198, A383199, A383200, A383201, A383202.

Sequence in context: A083584 A276780 A183916 * A199311 A146239 A083085

Adjacent sequences: A383194 A383195 A383196 * A383198 A383199 A383200

Keyword

nonn,base,easy

Author

Edwin Hermann, Apr 19 2025

Extensions

a(15)-a(24) from Alois P. Heinz, Apr 21 2025

Status

approved