A198850 2*8^n-1

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

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (9,-8).

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

Prog

(Magma) [2*8^n-1: n in [0..30]]

Crossrefs

Sequence in context: A337957 A337956 A073509 * A283120 A209404 A127595

Adjacent sequences: A198847 A198848 A198849 * A198851 A198852 A198853

Keyword

nonn,easy

Author

Vincenzo Librandi, Oct 31 2011

Status

approved