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%I #26 Sep 08 2022 08:45:27
%S 1,1,1,1,1,2,5,29,869,756029,285790302433,16335219393063437264866,
%T 9201358366190200404401435237110861938769705
%N a(n) = 3*a(n-1)*a(n-2)*a(n-3)*a(n-4) - a(n-5), with a(1)=a(2)=a(3)=a(4)=a(5)=1.
%H G. C. Greubel, <a href="/A121910/b121910.txt">Table of n, a(n) for n = 1..17</a>
%p a:= proc(n) option remember;
%p if n<6 then 1 else 3*a(n-1)*a(n-2)*a(n-3)*a(n-4) - a(n-5) fi;
%p end:
%p seq(a(n), n=1..15); # _G. C. Greubel_, Oct 07 2019
%t a[n_]:= a[n]= If[n<6, 1, 3*a[n-1]*a[n-2]*a[n-3]*a[n-4] - a[n-5]]; Table[a[n], {n, 15}] (* modified by _G. C. Greubel_, Oct 07 2019 *)
%o (PARI) my(m=15, v=concat([1,1,1,1,1], vector(m-5))); for(n=6, m, v[n] = 3*v[n-1] *v[n-2]*v[n-3]*v[n-4] - v[n-5]); v \\ _G. C. Greubel_, Oct 07 2019
%o (Magma) [n lt 6 select 1 else 3*Self(n-1)*Self(n-2)*Self(n-3)*Self(n-4) - Self(n-5): n in [1..15]]; // _G. C. Greubel_, Oct 07 2019
%o (Sage)
%o def a(n):
%o if (n<6): return 1
%o else: return 3*a(n-1)*a(n-2)*a(n-3)*a(n-4) - a(n-5)
%o [a(n) for n in (1..15)] # _G. C. Greubel_, Oct 07 2019
%o (GAP)
%o a:= function(n)
%o if n<6 then return 1;
%o else return 3*a(n-1)*a(n-2)*a(n-3)*a(n-4) - a(n-5);
%o fi;
%o end;
%o List([1..15], n-> a(n) ); # _G. C. Greubel_, Oct 05 2019
%Y Cf. A072879, A121897.
%K nonn
%O 1,6
%A _Roger L. Bagula_, Sep 09 2006
%E Edited by _N. J. A. Sloane_, Sep 15 2006
%E Definition adapted to offset by _Georg Fischer_, Jun 18 2021
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