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A139802 a(1)=1, a(2)=2, a(n)=n^a(n-2) 1
1, 2, 3, 16, 125, 2821109907456, 4337654948097993282537354757263188251697832994620405101744893017744569432720994168089672192211758909320807 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Exponential double factorial.

The next term is too large to include.

LINKS

Table of n, a(n) for n=0..6.

EXAMPLE

a(1)=1

a(2)=2

a(3)=3^1=3

a(4)=4^2=16

a(5)=5^3=125

a(6)=6^16=2821109907456

etc.

MAPLE

P:=proc(n) local a, b, c, i; a:=1; b:=2; print(a); print(b); for i from 3 by 1 to n do c:=i^a; print(c); a:=b; b:=c; od; end: P(10);

CROSSREFS

Cf. A049384.

Sequence in context: A254382 A067848 A269067 * A292207 A063666 A006247

Adjacent sequences:  A139799 A139800 A139801 * A139803 A139804 A139805

KEYWORD

easy,nonn

AUTHOR

Paolo P. Lava and Giorgio Balzarotti, May 22 2008

STATUS

approved

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Last modified May 25 07:56 EDT 2020. Contains 334585 sequences. (Running on oeis4.)