A086574 a(n) = 3*(10^n-1).

0, 27, 297, 2997, 29997, 299997, 2999997, 29999997, 299999997, 2999999997, 29999999997, 299999999997, 2999999999997, 29999999999997, 299999999999997, 2999999999999997, 29999999999999997, 299999999999999997, 2999999999999999997, 29999999999999999997, 299999999999999999997

Offset

0,2

Comments

Original definition: a(n) = k where R(k+3) = 3. [Here R = reverse = A004086, not R = repunit = A002275 as in some other places.]

Links

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

Index entries for linear recurrences with constant coefficients, signature (11,-10).

Formula

a(n) = 3*9*A002275(n) = 3*A002283(n); R(a(n))=A086579(n).

a(0)=0, a(1)=27, a(n)=11*a(n-1)-10*a(n-2). - Harvey P. Dale, Nov 28 2015

G.f.: 27*x/((1 - x)*(1 - 10*x)). - Ilya Gutkovskiy, Jul 29 2016

Mathematica

Join[{0}, Table[FromDigits[Join[PadRight[{2}, n, 9], {7}]], {n, 20}]] (* or *) LinearRecurrence[{11, -10}, {0, 27}, 30] (* Harvey P. Dale, Nov 28 2015 *)

Prog

(PARI) a(n)=10^n*3-3 \\ M. F. Hasler, Jul 29 2016

Crossrefs

One of family of sequences of form a(n) = k, where R(k+m) = m, m=1 to 9; m=1: A002283, m=2: A086573, m=3: A086574, m=4: A086575, m=5: A086576, m=6: A086577, m=7: A086578, m=8: A086579, m=9: A086580.

The restriction to positive indices yields A083813. - M. F. Hasler, Jul 29 2016

Sequence in context: A202126 A022687 A083813 * A274832 A125415 A119295

Adjacent sequences: A086571 A086572 A086573 * A086575 A086576 A086577

Keyword

nonn,easy

Author

Ray Chandler, Jul 22 2003

Extensions

Edited by M. F. Hasler, Jul 29 2016

Status

approved