A064747 a(n) = n*9^n + 1.

1, 10, 163, 2188, 26245, 295246, 3188647, 33480784, 344373769, 3486784402, 34867844011, 345191655700, 3389154437773, 33044255768278, 320275094369455, 3088366981419736, 29648323021629457, 283512088894331674, 2701703435345984179, 25666182635786849692, 243153309181138576021

Offset: 0

Author

N. J. A. Sloane, Oct 19 2001

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Paul Leyland, Factors of Cullen and Woodall numbers.
• Paul Leyland, Generalized Cullen and Woodall numbers.
• Index entries for linear recurrences with constant coefficients, signature (19,-99,81).

Crossrefs

Cf. A158749.

Programs

Magma

[ n*9^n+1: n in [0..20]]; // Vincenzo Librandi, Sep 16 2011

Mathematica

Table[n*9^n+1,{n,0,20}] (* or *) LinearRecurrence[{19,-99,81},{1,10,163},20]

Formula

a(n) = 19*a(n-1) - 99*a(n-2) + 81*a(n-3); a(0)=1, a(1)=10, a(2)=163. - Harvey P. Dale, Jan 16 2016

From Elmo R. Oliveira, Sep 09 2024: (Start)

G.f.: -(72*x^2 - 9*x + 1)/((x - 1)*(9*x - 1)^2).

E.g.f.: exp(x)*(9*x*exp(8*x) + 1).

a(n) = A158749(n) + 1. (End)