A013895 a(n) = 20^(5*n + 2).
400, 1280000000, 4096000000000000, 13107200000000000000000, 41943040000000000000000000000, 134217728000000000000000000000000000, 429496729600000000000000000000000000000000, 1374389534720000000000000000000000000000000000000
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..50
- Tanya Khovanova, Recursive Sequences.
- Index entries for linear recurrences with constant coefficients, signature (3200000).
Programs
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Magma
[20^(5*n+2): n in [0..10]]; // Vincenzo Librandi, May 27 2011
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Maple
A013895:=n->20^(5*n+2): seq(A013895(n), n=0..10); # Wesley Ivan Hurt, Nov 17 2015
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Mathematica
20^(5 Range[0, 10] + 2) (* or *) CoefficientList[Series[-400/(3200000*x - 1), {x, 0, 10}], x] (* Wesley Ivan Hurt, Nov 17 2015 *) -
PARI
Vec(-400/(3200000*x-1) + O(x^10)) \\ Colin Barker, Nov 17 2015
Formula
a(n) = 3200000*a(n-1), a(0)=400. - Vincenzo Librandi, May 27 2011
G.f.: -400/(3200000*x-1). - Colin Barker, Nov 17 2015
From Elmo R. Oliveira, Jul 13 2025: (Start)
E.g.f.: 400*exp(3200000*x).