A199214 a(n) = 3*5^n+1.

4, 16, 76, 376, 1876, 9376, 46876, 234376, 1171876, 5859376, 29296876, 146484376, 732421876, 3662109376, 18310546876, 91552734376, 457763671876, 2288818359376, 11444091796876, 57220458984376, 286102294921876, 1430511474609376

Offset: 0

Author

Vincenzo Librandi, Nov 04 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 (6,-5).

Crossrefs

Cf. A083065.

Programs

Magma

[3*5^n+1: n in [0..30]];

Mathematica

LinearRecurrence[{6,-5},{4,16},30] (* Harvey P. Dale, Jul 08 2013 *)

Formula

a(n) = 4*A083065(n).

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

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

G.f.: 4*(1-2*x)/((1-x)*(1-5*x)). - Bruno Berselli, Nov 04 2011