Problems & Puzzles:
Large three consecutive semiprimes
Dmitry Kamenetsky asks for the largest
known set of trio of consecutive integers that are
Just digging around with a simple code in
Ubasic I found a trio of integers of 200 digits: N-1, N &
N+1 where N=10^199+10570618. For sure larger examples may be
found by you. Or perhaps larger trios may have already been
reported somewhere out there.
Q. Send your largest
Contribution came from J. K. Andersen
Andersen wrote on Jun 16, 2017:
I worked on this in 2003.
"p=672066*4691#+1 and q=2329500*4691#+1 are primes.
p * q, 2 * (pq+1)/2, 3 * (pq+2)/3 are 4021-digit
Six days later (Jun 22, 2017) he added:
p=2585292*7001#+1 and q=5576994*7001#+1 are primes.
p * q, 2 * (p*q+1)/2, 3 * (p*q+2)/3 are 6032-digit
All prp tests and primality proofs were made with