A155666 a(n) = 9^n - 8^n + 1.
1, 2, 18, 218, 2466, 26282, 269298, 2685818, 26269506, 253202762, 2413042578, 22791125018, 213710059746, 1992110014442, 18478745943858, 170706760005818, 1571545212141186, 14425381885981322, 132080236787517138, 1206736529597136218, 11004743954450081826, 100195617094657583402
Offset: 0
Links
- Paolo Xausa, Table of n, a(n) for n = 0..1000
- Index entries for linear recurrences with constant coefficients, signature (18,-89,72).
Crossrefs
Programs
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Mathematica
Table[9^n-8^n+1,{n,0,20}] (* or *) LinearRecurrence[{18,-89,72},{1,2,18},20] (* Harvey P. Dale, Aug 16 2015 *)
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PARI
a(n)=9^n-8^n+1 \\ Charles R Greathouse IV, Jun 11 2015
Formula
G.f.: 1/(1-9*x)-1/(1-8*x)+1/(1-x).
E.g.f.: exp(9*x)-exp(8*x)+exp(x).
a(n) = 17*a(n-1)-72*a(n-2)+56 with a(0) = 1, a(1) = 2. - Vincenzo Librandi, Jul 21 2010
Comments