A198762 3*5^n-1= 2*A057651(n).

2, 14, 74, 374, 1874, 9374, 46874, 234374, 1171874, 5859374, 29296874, 146484374, 732421874, 3662109374, 18310546874, 91552734374, 457763671874, 2288818359374, 11444091796874, 57220458984374, 286102294921874, 1430511474609374

Offset

0,1

Links

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

Index entries for linear recurrences with constant coefficients, signature (6,-5).

Formula

a(n) = 5*a(n-1)+4.

a(n) = 6*a(n-1)-5*a(n-2), n>1.

G.f.: 2*(1 + x)/(1 - 6*x + 5*x^2). - Vincenzo Librandi, Jan 04 2013

Mathematica

CoefficientList[Series[2*(1 + x)/(1 - 6*x + 5*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 04 2013 *)
LinearRecurrence[{6, -5}, {2, 14}, 30] (* Harvey P. Dale, Mar 19 2013 *)

Prog

(Magma) [(3*5^n-1): n in [0..30]]

Crossrefs

Cf. A024049, A057651, A081655.

Sequence in context: A138156 A280392 A192809 * A119913 A296983 A304049

Adjacent sequences: A198759 A198760 A198761 * A198763 A198764 A198765

Keyword

nonn,easy

Author

Vincenzo Librandi, Oct 30 2011

Status

approved