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A263043 a(n)=n for n = 1..5; for n>=6, a(n) = a(n-5)*a(n-3)*a(n-1) - a(n-4)*a(n-2).

%I A263043 #20 Dec 21 2024 12:24:16
%S A263043 1,2,3,4,5,7,41,587,16231,3323246,13654552343,9086706651503151,
%T A263043 17725851219520961162682469,3928527920941441960398255684700870518131,
%U A263043 118631177920294161985904111240557003105520588984802122222460259
%N A263043 a(n)=n for n = 1..5; for n>=6, a(n) = a(n-5)*a(n-3)*a(n-1) - a(n-4)*a(n-2).
%t A263043 nxt[{a_,b_,c_,d_,e_}]:={b,c,d,e,a*c*e-b*d}; NestList[nxt,{1,2,3,4,5},15][[;;,1]] (* _Harvey P. Dale_, Dec 21 2024 *)
%o A263043 (PARI) a(n) = if(n<6, n, a(n-5)*a(n-3)*a(n-1)-a(n-4)*a(n-2));
%o A263043 vector(20, n, a(n)) \\ _Altug Alkan_, Oct 08 2015
%o A263043 (Magma) [n le 5 select n else Self(n-5)*Self(n-3)*Self(n-1)-Self(n-4)*Self(n-2): n in [1..20]]; // _Vincenzo Librandi_, Oct 09 2015
%K A263043 nonn
%O A263043 1,2
%A A263043 _Gianmarco Giordano_, Oct 08 2015
%E A263043 More terms from _Altug Alkan_, Oct 08 2015