login
a(n) = 25^(4*n+3).
1

%I #19 Sep 04 2024 19:05:44

%S 15625,6103515625,2384185791015625,931322574615478515625,

%T 363797880709171295166015625,142108547152020037174224853515625,

%U 55511151231257827021181583404541015625,21684043449710088680149056017398834228515625,8470329472543003390683225006796419620513916015625

%N a(n) = 25^(4*n+3).

%C Subsequence of A000351. - _Michel Marcus_, Jun 12 2016.

%H Vincenzo Librandi, <a href="/A191560/b191560.txt">Table of n, a(n) for n = 0..100</a>

%H <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (390625).

%F G.f.: (15625)/(1-390625*x). - _Vincenzo Librandi_, Jun 12 2016

%F a(n) = 5^(8*n+6) = 5^(2*(4*n+3)) from Michel Marcus Jun 12 2016

%t Table[25^(4 n + 3), {n, 0, 10}] (* _Vincenzo Librandi_, Jun 12 2016 *)

%o (Magma) [25^(4*n+3): n in [0..10]];

%K nonn,easy

%O 0,1

%A _Vincenzo Librandi_, Jul 07 2011