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A287826 Number of sequences over the alphabet {0,1,...,9} such that no two consecutive terms have distance 2. 0
1, 10, 84, 708, 5968, 50308, 424080, 3574860, 30134944, 254028100, 2141377008, 18051134892, 152165391616, 1282706408548, 10812811724688, 91148603152524, 768354066287200, 6476983198439812, 54598931916359472, 460251829451302764, 3879778213203474880 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..20.

Index entries for linear recurrences with constant coefficients, signature (10, -13, -2).

FORMULA

a(n) = 10*a(n-1) - 13*a(n-2) - 2a(n-3), a(0)=1, a(1)=10, a(2)=84.

G.f.: (1 - 3 x^2)/(1 - 10 x + 13 x^2 + 2 x^3).

MATHEMATICA

LinearRecurrence[{10, -13, -2}, {1, 10, 84}, 40]

PROG

(Python)

def a(n):

.if n in [0, 1, 2]:

..return [1, 10, 84][n]

.return 10*a(n-1)-13*a(n-2)-2*a(n-3)

CROSSREFS

Cf. A040000, A003945, A083318, A078057, A003946, A126358, A003946, A055099, A003947, A015448, A126473. A287804-A287819. A287825-A287831.

Sequence in context: A090763 A016131 A027310 * A335647 A155593 A239990

Adjacent sequences:  A287823 A287824 A287825 * A287827 A287828 A287829

KEYWORD

nonn,easy

AUTHOR

David Nacin, Jun 02 2017

STATUS

approved

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Last modified March 2 06:13 EST 2021. Contains 341742 sequences. (Running on oeis4.)