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A173501
a(1) = 2, a(2) = 3, a(n) = 6^(2^(n-3)) for n >= 3.
5
2, 3, 6, 36, 1296, 1679616, 2821109907456, 7958661109946400884391936, 63340286662973277706162286946811886609896461828096
OFFSET
1,1
COMMENTS
Except for first three terms, a(n) = (a(n-1))^2.
Essentially the same as A165424. - R. J. Mathar, Feb 21 2010
LINKS
FORMULA
a(n) = Product_{i=1..n-1} a(i) with a(1) = 2 and a(2) = 3.
a(n) = 6^(2^(n-3)) = A000400(A000079(n-3)) for n>2.
MATHEMATICA
Table[If[n<3, n+1, 6^(2^(n-3))], {n, 10}] (* G. C. Greubel, Apr 25 2021 *)
PROG
(SageMath) [2, 3]+[6^(2^(n-3)) for n in (3..10)] # G. C. Greubel, Apr 25 2021
(PARI) a(n) = if(n<=2, n+1, 6^(2^(n-3))) \\ Felix Fröhlich, Apr 25 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Giovanni Teofilatto, Feb 20 2010
EXTENSIONS
Definition corrected by Glenn Tesler, Aug 19 2017
STATUS
approved