

A125249


Numbers n for which the absolute values of the abundances of n, n^2 and n^3 are all prime numbers.


0



289, 201601, 222784, 638401, 868562, 910116, 4694048, 4950625, 8994001, 9054081, 19855936, 30085225, 32385152, 47623801, 55100929, 72182016, 78952178, 85099058, 86303522, 91910569, 104040000, 105678400, 111175936, 112530002, 128504896, 133702969, 193043236, 204404209, 216001809, 237961476
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OFFSET

1,1


LINKS

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


EXAMPLE

n=289; The abundance of 289 is 271, the abundance of 83521 (289^2) is 78301, the abundance of 24137569 (289^3) is 22628971  all of which are negatives of primes.


PROG

(PARI) {for(n=1, 1000000, if(isprime(abs(sigma(n)2*n))&&isprime(abs(sigma(n^2)2*n^2))&&isprime(abs(sigma(n^3)2*n^3)), print1(n, ", ")))}


CROSSREFS

Cf. A088005, A125236, A125237.
Sequence in context: A226747 A260866 A252360 * A013761 A013883 A180701
Adjacent sequences: A125246 A125247 A125248 * A125250 A125251 A125252


KEYWORD

nonn


AUTHOR

Jason G. Wurtzel, Nov 26 2006


EXTENSIONS

More terms from Stefan Steinerberger, May 29 2007
a(21)a(24) from Donovan Johnson, Feb 19 2009
a(25)a(30) from Jason G. Wurtzel, Sep 24 2014


STATUS

approved



