A112953 a(1) = 0; a(n) = pi(n)^pi(n) for n>1, where pi is the prime counting function (A000720).

0, 1, 4, 4, 27, 27, 256, 256, 256, 256, 3125, 3125, 46656, 46656, 46656, 46656, 823543, 823543, 16777216, 16777216, 16777216, 16777216, 387420489, 387420489, 387420489, 387420489, 387420489, 387420489, 10000000000, 10000000000

Offset

1,3

Links

Table of n, a(n) for n=1..30.

Example

pi(5) = 3, so a(5) = 3^3 = 27.
pi(11) = 5, so a(11) = 5^5 = 3125.

Mathematica

Join[{0}, #^#&/@PrimePi[Range[2, 30]]] (* Harvey P. Dale, Sep 19 2019 *)

Prog

(PARI) a(n) = if (n==1, 0, primepi(n)^primepi(n)); \\ Michel Marcus, Jun 01 2013; corrected Jun 13 2022

Crossrefs

Cf. A000720 (pi).

Sequence in context: A221276 A117429 A132650 * A110139 A078146 A066836

Adjacent sequences: A112950 A112951 A112952 * A112954 A112955 A112956

Keyword

base,easy,nonn

Author

Alexandre Wajnberg, Jan 02 2006

Extensions

More terms from Michel Marcus, Jun 01 2013

Status

approved