1,1

Next term after 4823 is greater than 10000. - Ryan Propper (rpropper(AT)stanford.edu), Jun 30 2005

Contribution from M. F. Hasler and F. Firoozbakht (mymontain(AT)yahoo.com), Oct 30 2009: (Start)

If Q is a perfect number such that gcd(Q, 3(3^a(n)-4))=1 then m=3^(a(n)-1)

(3^a(n)-4)Q is a solution of the equation sigma(x)=3(x+Q). This is a result of

the following theorem.

Theorem : If for a prime q, Q is a (q-1)-perfect number and p=q^k-q-1 is

a prime such that gcd(Q, p*q)=1, then m=p*q^(k-1)*Q is a solution of the

equation sigma(x)=q(x+Q). The proof is easy. (End)

Do[ If[ PrimeQ[3^n - 4], Print[n] ], {n, 1, 3000} ]

Sequence in context: A127078 A076383 A024766 this_sequence A065398 A084838 A051694

Adjacent sequences: A058956 A058957 A058958 this_sequence A058960 A058961 A058962

nonn

Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 13 2001

One additional term, corresponding to a certified prime, from Ryan Propper (rpropper(AT)stanford.edu), Jun 30 2005