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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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified November 27 00:20 EST 2022. Contains 358362 sequences. (Running on oeis4.)