A072713 a(1)=a(2)=a(3)=a(4)=a(5)=1; for n>5, a(n)*a(n-5) = a(n-1)*a(n-2)*a(n-3)*a(n-4)+1.
1, 1, 1, 1, 1, 2, 3, 7, 43, 1807, 815861, 147917502976, 1339566593057489572791, 6793440021984612817314824762112917427331, 607759339422199886496126580428414916308278553796099069562650354036190535151
Offset: 1
Keywords
Links
- Seiichi Manyama, Table of n, a(n) for n = 1..19
Programs
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Mathematica
nxt[{a_,b_,c_,d_,e_}]:={b,c,d,e,(b*c*d*e+1)/a}; Join[{1,1,1,1}, Transpose[ NestList[nxt,{1,1,1,1,1},15]][[5]]] (* Harvey P. Dale, Oct 03 2012 *)