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A176338 a(n) = 1 + (1-3^n)*a(n-1) for n >=1, a(0) = 0.

%I A176338 #17 Dec 31 2024 14:44:03
%S A176338 0,1,-7,183,-14639,3542639,-2579041191,5637784043527,
%T A176338 -36983863325537119,727916397973221576159,-42982007467522787629036631,
%U A176338 7614090694841791737333323035127,-4046432358866721800888421193787892879
%N A176338 a(n) = 1 + (1-3^n)*a(n-1) for n >=1, a(0) = 0.
%H A176338 G. C. Greubel, <a href="/A176338/b176338.txt">Table of n, a(n) for n = 0..64</a>
%p A176338 A176338 := proc(n)
%p A176338     if n = 0 then
%p A176338         0;
%p A176338     else
%p A176338         1+(1-3^n)*procname(n-1) ;
%p A176338     end if;
%p A176338 end proc: # _R. J. Mathar_, May 04 2013
%t A176338 a[n_, q_]:= a[n, q]= If[n==0, 0, (1-q^n)*a[n-1, q] +1]; Table[a[n, 3], {n,0,15}]
%t A176338 nxt[{n_,a_}]:={n+1,a(1-3^(n+1))+1}; NestList[nxt,{0,0},20][[;;,2]] (* _Harvey P. Dale_, Dec 31 2024 *)
%o A176338 (PARI) q=3; a(n,q) = if(n==0, 0, 1 -(q^n-1)*a(n-1,q) );
%o A176338 vector(16, n, a(n-1,3)) \\ _G. C. Greubel_, Dec 07 2019
%o A176338 (Magma)
%o A176338 function a(n,q)
%o A176338   if n eq 0 then return 0;
%o A176338   else return 1 - (q^n-1)*a(n-1,q);
%o A176338   end if; return a; end function;
%o A176338 [a(n,3): n in [0..15]]; // _G. C. Greubel_, Dec 07 2019
%o A176338 (Sage)
%o A176338 def a(n, q):
%o A176338     if (n==0): return 0
%o A176338     else: return 1 - (q^n-1)*a(n-1,q)
%o A176338 [a(n,3) for n in (0..15)] # _G. C. Greubel_, Dec 07 2019
%o A176338 (GAP)
%o A176338 a:= function(n,q)
%o A176338     if n=0 then return 0;
%o A176338     else return 1 - (q^n-1)*a(n-1,q);
%o A176338 fi; end; List([0..15], n-> a(n,3) ); # _G. C. Greubel_, Dec 07 2019
%Y A176338 Cf. A176337.
%K A176338 sign,easy
%O A176338 0,3
%A A176338 _Roger L. Bagula_, Apr 15 2010