A199416 2*7^n+1.

3, 15, 99, 687, 4803, 33615, 235299, 1647087, 11529603, 80707215, 564950499, 3954653487, 27682574403, 193778020815, 1356446145699, 9495123019887, 66465861139203, 465261027974415, 3256827195820899, 22797790370746287

Offset

0,1

Links

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

Index entries for linear recurrences with constant coefficients, signature (8,-7).

Formula

a(n) = 3*A083076(n).

a(n) = 7*a(n-1)-6.

a(n) = 8*a(n-1)-7*a(n-2).

G.f.: 3*(1-3*x)/((1-x)*(1-7*x)).

Prog

(Magma) [2*7^n+1: n in [0..30]];

Crossrefs

Sequence in context: A370676 A186264 A140286 * A046635 A208426 A168344

Adjacent sequences: A199413 A199414 A199415 * A199417 A199418 A199419

Keyword

nonn,easy

Author

Vincenzo Librandi, Nov 06 2011

Status

approved