The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A152859 Tower of prime powers: a(n)=prime(n)^a(n-1), a(0)=0. 1
 0, 1, 3, 125, 4337654948097993282537354757263188251697832994620405101744893017744569432720994168089672192211758909320807 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Originally called "Exprimorial numbers (exponential prime factorials)", the strict analog would be "exponential primorial". [Editor's Note] LINKS Table of n, a(n) for n=0..4. J. Sondow, Exponential Factorial Wikipedia, Factorial FORMULA a(n) = 0 if n = 0; a(n) = prime(n) ^ a(n - 1), n >= 1. EXAMPLE a(4) = 7 ^ a(3) = 7 ^ 125. a(5) = 11 ^ a(4) has approximately 4.5 * 10^105 digits, starting with 335856... and ending in ...815171. PROG (C) unsigned long Exprimorial(unsigned int n) { if (n == 0) return 0; return pow(prime(n), Exprimorial(n - 1)); } (PARI) vector(4, i, t=if(i==1, 1, prime(i)^t)) /* indices are shifted by 1 */ \\ M. F. Hasler, Nov 01 2009 CROSSREFS Cf. A002110, A049384. Cf. A140319 (alternate definition: start with a(0)=1). - Paolo P. Lava, Jul 31 2018 Sequence in context: A085531 A130614 A114877 * A241647 A157547 A160879 Adjacent sequences: A152856 A152857 A152858 * A152860 A152861 A152862 KEYWORD nonn AUTHOR ShaoJun Ying (dolphinysj(AT)gmail.com), Dec 14 2008 EXTENSIONS Edited by M. F. Hasler, Nov 01 2009 STATUS approved

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

Last modified September 29 02:45 EDT 2023. Contains 365749 sequences. (Running on oeis4.)