

A140319


Exponential primorial: a(n)=prime(n)^a(n1), a(0)=1, where prime(n)=A000040(n).


4




OFFSET

0,2


COMMENTS

The next term is too large to include.


LINKS

Table of n, a(n) for n=0..3.
J. Sondow, "Exponential Factorial."


EXAMPLE

a(1) = prime(1)^a(0) = 2^1 = 2.
a(2) = 3^2 = 9.
a(3) = 5^9 = 1953125.
a(4) = 7^1953125 has 1650583 digits, starting with 12864794... and ending in ...31920807. [M. F. Hasler, Nov 03 2009]


MAPLE

P:=proc(n) local a, i; a:=2; print(a); for i from 2 by 1 to n do a:=ithprime(i)^a; print(a); od; end: P(5);


PROG

(PARI) A140319(n)=if(n, prime(n)^A140319(n1), 1) \\ [M. F. Hasler, Nov 03 2009]


CROSSREFS

Cf. A002110, A049384, A139802.
Cf. A152859 (alternate definition: start with a(0)=0), A167155. [M. F. Hasler, Nov 03 2009]
Sequence in context: A049384 A132859 A103562 * A120314 A050924 A181500
Adjacent sequences: A140316 A140317 A140318 * A140320 A140321 A140322


KEYWORD

easy,nonn


AUTHOR

Paolo P. Lava and Giorgio Balzarotti, May 26 2008


EXTENSIONS

Corrected offset/definition, added initial term a(0)=1 M. F. Hasler, Nov 03 2009


STATUS

approved



