A050919 a(n) = n*7^n + 1.

1, 8, 99, 1030, 9605, 84036, 705895, 5764802, 46118409, 363182464, 2824752491, 21750594174, 166095446413, 1259557135292, 9495123019887, 71213422649146, 531726889113617, 3954718737782520, 29311444762388083, 216579008522089718

Offset

0,2

Links

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

Paul Leyland, Factors of Cullen and Woodall numbers

Paul Leyland, Generalized Cullen and Woodall numbers

Index entries for linear recurrences with constant coefficients, signature (15,-63,49).

Formula

G.f.: -(42*x^2 - 7*x + 1)/((x-1)*(7*x-1)^2). [Colin Barker, Oct 14 2012]

Mathematica

Table[n*7^n+1, {n, 0, 20}] (* or *) LinearRecurrence[{15, -63, 49}, {1, 8, 99}, 20] (* Harvey P. Dale, Nov 23 2013 *)

Prog

(Magma) [ n*7^n+1: n in [0..20]]; // Vincenzo Librandi, Sep 16 2011

Crossrefs

Cf. A002064.

Sequence in context: A300114 A180927 A091801 * A341965 A230343 A376101

Adjacent sequences: A050916 A050917 A050918 * A050920 A050921 A050922

Keyword

nonn,easy

Author

N. J. A. Sloane, Dec 30 1999

Status

approved