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A162671 For n even a(n) = a(n-1) + a(n-2), for n odd a(n) = 100*a(n-1) + a(n-2), with a(0) = 0, a(1) = 1.

%I A162671 #19 Jan 20 2025 22:50:41
%S A162671 0,1,1,101,102,10301,10403,1050601,1061004,107151001,108212005,
%T A162671 10928351501,11036563506,1114584702101,1125621265607,113676711262801,
%U A162671 114802332528408,11593909964103601,11708712296632009,1182465139627304501,1194173851923936510,120599850332020955501
%N A162671 For n even a(n) = a(n-1) + a(n-2), for n odd a(n) = 100*a(n-1) + a(n-2), with a(0) = 0, a(1) = 1.
%H A162671 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,102,0,-1).
%F A162671 a(n) = 102*a(n-2)-a(n-4). G.f.: x*(1+x-x^2)/((x^2+10*x-1)*(x^2-10*x-1)). - _R. J. Mathar_, Jul 14 2009
%p A162671 a:= proc(n) a(n):= `if`(n<2, n, a(n-1)*(1+99*(n mod 2))+a(n-2)) end:
%p A162671 seq(a(n), n=0..22);  # _Alois P. Heinz_, Jan 20 2025
%t A162671 LinearRecurrence[{0,102,0,-1},{1,1,101,102},20] (* _Harvey P. Dale_, May 08 2020 *)
%Y A162671 Partly same as A041059 (and its palindromic partner-sequence A015446). A007318.
%K A162671 nonn,easy
%O A162671 0,4
%A A162671 _Mark Dols_, Jul 10 2009
%E A162671 More terms from _R. J. Mathar_, Jul 14 2009