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, 1595845325952240021, 11729463145748964148
Offset: 0
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).
Programs
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Magma
[ n*7^n+1: n in [0..20]]; // Vincenzo Librandi, Sep 16 2011
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Mathematica
Table[n*7^n+1,{n,0,20}] (* or *) LinearRecurrence[{15,-63,49},{1,8,99},20] (* Harvey P. Dale, Nov 23 2013 *)
Formula
G.f.: -(42*x^2 - 7*x + 1)/((x-1)*(7*x-1)^2). - Colin Barker, Oct 14 2012
From Elmo R. Oliveira, May 03 2025: (Start)
E.g.f.: exp(x)*(1 + 7*x*exp(6*x)).
a(n) = 15*a(n-1) - 63*a(n-2) + 49*a(n-3).
a(n) = A036293(n) + 1. (End)