OFFSET
1,1
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
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