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A013895
a(n) = 20^(5*n+2).
1
400, 1280000000, 4096000000000000, 13107200000000000000000, 41943040000000000000000000000, 134217728000000000000000000000000000, 429496729600000000000000000000000000000000, 1374389534720000000000000000000000000000000000000
OFFSET
0,1
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
a(n) = A009964(A016873(n)). - Wesley Ivan Hurt, Nov 17 2015
MAPLE
A013895:=n->20^(5*n+2): seq(A013895(n), n=0..10); # Wesley Ivan Hurt, Nov 17 2015
MATHEMATICA
20^(5 Range[0, 10] + 2) (* or *) CoefficientList[Series[-400/(3200000*x - 1), {x, 0, 10}], x] (* Wesley Ivan Hurt, Nov 17 2015 *)
PROG
(Magma) [20^(5*n+2): n in [0..10]]; // Vincenzo Librandi, May 27 2011
(PARI) Vec(-400/(3200000*x-1) + O(x^10)) \\ Colin Barker, Nov 17 2015
CROSSREFS
Sequence in context: A197441 A268366 A013767 * A296904 A159890 A029705
KEYWORD
nonn,easy
STATUS
approved