login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..6.

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

Cf. A058798, A073888.

Sequence in context: A279834 A091409 A027891 * A332586 A211898 A318970

Adjacent sequences:  A073886 A073887 A073888 * A073890 A073891 A073892

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Aug 17 2002

EXTENSIONS

The next term is too large to include.

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 2 02:41 EDT 2020. Contains 335389 sequences. (Running on oeis4.)