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A051674 Prime(n)^prime(n). 80
4, 27, 3125, 823543, 285311670611, 302875106592253, 827240261886336764177, 1978419655660313589123979, 20880467999847912034355032910567, 2567686153161211134561828214731016126483469 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

n such that bigomega(n)^(bigomega(n))=n, where bigomega=A001222. - Lekraj Beedassy, Aug 21 2004

Positive n such that n' = n, where n' is the arithmetic derivative of n. - T. D. Noe, Oct 12 2004

David Beckwith proposes (in the AMM reference): "Let n be a positive integer and let p be a prime number. Prove that (p^p) | n! implies that (p^(p + 1)) | n!" - Jonathan Vos Post, Feb 20 2006

Subsequence of A100716; A003415(m*a(n))=A129283(m)*a(n), especially A003415(a(n))=a(n). - Reinhard Zumkeller, Apr 07 2007

REFERENCES

J.-M. De Koninck & A. Mercier, 1001 Problemes en Theorie Classique Des Nombres, Problem 740 pp. 95; 312, Ellipses Paris 2004.

LINKS

T. D. Noe, Table of n, a(n) for n = 1..40

David Beckwith, Problem 11158, American Mathematical Monthly, Vol. 112, No. 5 (May 2005), p. 468.

Jurij Kovic, The Arithmetic Derivative and Antiderivative, Journal of Integer Sequences, Vol. 15 (2012), #12.3.8.

EXAMPLE

a(1) = 2^2 = 4.

a(2) = 3^3 = 27.

a(3) = 5^5 = 3125.

MATHEMATICA

Array[Prime[ # ]^Prime[ # ] &, 12] (* Vladimir Joseph Stephan Orlovsky, May 01 2008 *)

PROG

(Haskell)

a051674_list = map (\p -> p ^ p) a000040_list

-- Reinhard Zumkeller, Jan 21 2012

(PARI) a(n)=n=prime(n); n^n \\ Charles R Greathouse IV, Mar 20 2013

(MAGMA) [p^p: p in PrimesUpTo(30)]; // Vincenzo Librandi, Mar 27 2014

(Python) from gmpy2 import mpz

[mpz(prime(n))**mpz(prime(n)) for n in range(1, 100)] # Chai Wah Wu, Jul 28 2014

CROSSREFS

Cf. A000040, A003415 (arithmetic derivative of n), A129150, A129151, A129152, A048102, A072873 (multiplicative closure), A104126.

Subsequence of A100717; A203908(a(n)) = 0.

Sequence in context: A066352 A249105 A249110 * A132641 A008973 A132646

Adjacent sequences:  A051671 A051672 A051673 * A051675 A051676 A051677

KEYWORD

nonn,easy

AUTHOR

Asher Auel (asher.auel(AT)reed.edu)

STATUS

approved

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Last modified December 20 13:53 EST 2014. Contains 252266 sequences.