A037486 - OEIS

A037486

Base 9 digits are, in order, the first n terms of the periodic sequence with initial period 1,2.

1, 11, 100, 902, 8119, 73073, 657658, 5918924, 53270317, 479432855, 4314895696, 38834061266, 349506551395, 3145558962557, 28310030663014, 254790275967128, 2293112483704153

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..17.

Index entries for linear recurrences with constant coefficients, signature (9,1,-9).

FORMULA

a(n) = 9*a(n-1) + a(n-2) - 9*a(n-3).

G.f.: x*(1+2*x)/((1-9*x)*(1-x^2)). a(n) = (11*9^n+4*(-1)^n-15)/80. - Bruno Berselli, Jan 20 2011

MATHEMATICA

Table[FromDigits[PadRight[{}, n, {1, 2}], 9], {n, 20}] (* or *) LinearRecurrence[ {9, 1, -9}, {1, 11, 100}, 20] (* Harvey P. Dale, Feb 15 2020 *)

CROSSREFS

Sequence in context: A081906 A098296 A037542 * A103720 A322719 A127806

Adjacent sequences: A037483 A037484 A037485 * A037487 A037488 A037489

KEYWORD

nonn,base,easy

AUTHOR

Clark Kimberling

STATUS

approved