A064757 a(n) = n*11^n - 1.
10, 241, 3992, 58563, 805254, 10629365, 136410196, 1714871047, 21221529218, 259374246009, 3138428376720, 37661140520651, 448795257871102, 5316497670165373, 62658722541234764, 735195677817154575, 8592599484487994106, 100078511642860166657, 1162022718519876379528
Offset: 1
Links
- Vincenzo Librandi, Table of n, a(n) for n = 1..900
- Paul Leyland, Factors of Cullen and Woodall numbers.
- Paul Leyland, Generalized Cullen and Woodall numbers.
- Index entries for linear recurrences with constant coefficients, signature (23,-143,121).
Crossrefs
Programs
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Magma
[n*11^n - 1: n in [1..20]]; // Vincenzo Librandi, Sep 16 2011
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Maple
k:= 11; f:= gfun:-rectoproc({1 + (k-1)*n + k*n*a(n-1) - (n-1)*a(n) = 0, a(1) = k-1}, a(n), remember): map(f, [$1..20]); # Georg Fischer, Feb 19 2021 -
Mathematica
Table[n*11^n-1,{n,20}] (* Harvey P. Dale, May 12 2019 *)
Formula
From Elmo R. Oliveira, Sep 07 2024: (Start)
G.f.: x*(121*x^2 - 11*x - 10)/((x - 1)*(11*x - 1)^2).
E.g.f.: 1 + exp(x)*(11*x*exp(10*x) - 1).
a(n) = 23*a(n-1) - 143*a(n-2) + 121*a(n-3) for n > 3.
a(n) = A064749(n) - 2. (End)
Comments