The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 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

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.

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