A064746 a(n) = n*8^n + 1.
1, 9, 129, 1537, 16385, 163841, 1572865, 14680065, 134217729, 1207959553, 10737418241, 94489280513, 824633720833, 7146825580545, 61572651155457, 527765581332481, 4503599627370497, 38280596832649217, 324259173170675713, 2738188573441261569, 23058430092136939521
Offset: 0
Links
- Harry J. Smith, Table of n, a(n) for n = 0..150
- Paul Leyland, Factors of Cullen and Woodall numbers.
- Paul Leyland, Generalized Cullen and Woodall numbers.
- Index entries for linear recurrences with constant coefficients, signature (17,-80,64).
Programs
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Mathematica
Table[n*8^n+1,{n,0,20}] (* or *) LinearRecurrence[{17,-80,64},{1,9,129},20] (* Harvey P. Dale, Jul 24 2012 *) -
PARI
a(n) = { n*8^n + 1 } \\ Harry J. Smith, Sep 24 2009
Formula
a(n) = 17*a(n-1) - 80*a(n-2) + 64*a(n-3), a(0)=1, a(1)=9, a(2)=129. - Harvey P. Dale, Jul 24 2012
G.f.: -(56*x^2-8*x+1)/((x-1)*(8*x-1)^2). - Colin Barker, Oct 15 2012
From Elmo R. Oliveira, May 04 2025: (Start)
E.g.f.: exp(x)*(1 + 8*x*exp(7*x)).
a(n) = A036294(n) + 1. (End)