A198850 a(n) = 2*8^n - 1.

1, 15, 127, 1023, 8191, 65535, 524287, 4194303, 33554431, 268435455, 2147483647, 17179869183, 137438953471, 1099511627775, 8796093022207, 70368744177663, 562949953421311, 4503599627370495, 36028797018963967, 288230376151711743, 2305843009213693951, 18446744073709551615

Offset: 0

Author

Vincenzo Librandi, Oct 31 2011

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (9,-8).

Crossrefs

Cf. A013730.

Programs

Magma

[2*8^n-1: n in [0..30]];

Formula

a(n) = 8*a(n-1) + 7.

a(n) = 9*a(n-1) - 8*a(n-2), n > 1.

G.f.: (1+6*x)/((8*x-1)*(x-1)). - R. J. Mathar, Oct 31 2011

From Elmo R. Oliveira, Sep 13 2024: (Start)

E.g.f.: exp(x)*(2*exp(7*x) - 1).

a(n) = A013730(n) - 1. (End)