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A073889
a(1) = 1, a(2) = 3; for n>2, a(n) = {a(n-1)*a(n+1)}^(1/n) or a(n+1) = a(n)^n/a(n-1).
3
1, 3, 9, 243, 387420489, 35917545547686059365808220080151141317043
OFFSET
1,2
MAPLE
A073889:= proc(n) option remember;
if n<3 then 2*n-1;
else a(n-1)^(n-1)/a(n-2);
fi; end;
seq(A073889(n), n = 1..7); # G. C. Greubel, May 18 2020
MATHEMATICA
a[n_]:= a[n]= If[n<3, 2*n-1, a[n-1]^(n-1)/a[n-2]]; Table[a[n], {n, 7}] (* G. C. Greubel, May 18 2020 *)
PROG
(Magma) I:=[1, 3]; [n le 2 select I[n] else Self(n-1)^(n-1)/Self(n-2): n in [1..7]]; # G. C. Greubel, May 18 2020
(Sage)
def a(n):
if (n<3): return 2*n-1
else: return a(n-1)^(n-1)/a(n-2)
[a(n) for n in (1..7)] # G. C. Greubel, May 18 2020
CROSSREFS
Sequence in context: A279834 A091409 A027891 * A332586 A211898 A318970
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Aug 17 2002
EXTENSIONS
The next term is too large to include.
STATUS
approved