A208222 a(n) = (a(n-1)^3*a(n-3)^2+a(n-2))/a(n-4) with a(0)=a(1)=a(2)=a(3)=1.
1, 1, 1, 1, 2, 9, 731, 1562471573, 154486807085783774292345385804
Offset: 0
Keywords
Links
- Seiichi Manyama, Table of n, a(n) for n = 0..11
- Sergey Fomin and Andrei Zelevinsky, The Laurent phenomenon, arXiv:math/0104241v1 [math.CO] (2001), Advances in Applied Mathematics 28 (2002), 119-144.
Programs
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Maple
y:=proc(n) if n<4 then return 1: fi: return (y(n-1)^3*y(n-3)^2+y(n-2))/y(n-4): end: seq(y(n),n=0..9);
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Mathematica
a[n_]:=If[n<4,1, (a[n - 1]^3*a[n - 3]^2 + a[n - 2])/a[n - 4]]; Table[a[n], {n, 0, 11}] (* Indranil Ghosh, Mar 19 2017 *) nxt[{a_,b_,c_,d_}]:={b,c,d,(d^3 b^2+c)/a}; NestList[nxt,{1,1,1,1},10][[All,1]] (* Harvey P. Dale, May 31 2020 *)
Comments