A294327 a(n) = ((9*n + 8)*10^n - 8)/9.

0, 18, 288, 3888, 48888, 588888, 6888888, 78888888, 888888888, 9888888888, 108888888888, 1188888888888, 12888888888888, 138888888888888, 1488888888888888, 15888888888888888, 168888888888888888, 1788888888888888888, 18888888888888888888, 198888888888888888888

Offset

0,2

Links

Colin Barker, Table of n, a(n) for n = 0..900

Index entries for linear recurrences with constant coefficients, signature (21,-120,100).

Formula

From Colin Barker, Oct 28 2017: (Start)

G.f.: 18*x*(1 - 5*x) / ((1 - x)*(1 - 10*x)^2).

a(n) = 21*a(n-1) - 120*a(n-2) + 100*a(n-3) for n>2.

(End)

Prog

(PARI) concat(0, Vec(18*x*(1 - 5*x) / ((1 - x)*(1 - 10*x)^2) + O(x^30))) \\ Colin Barker, Oct 28 2017

Crossrefs

Cf. A002282, A294328, A294329.

Sequence in context: A035119 A230235 A288959 * A286725 A226998 A098303

Adjacent sequences: A294324 A294325 A294326 * A294328 A294329 A294330

Keyword

nonn,easy

Author

Seiichi Manyama, Oct 28 2017

Status

approved