1948447domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumber of numbers k in interval [(p_n)^2+1, (p_n)^4] for which lpf(k-1)>lpf(k-3)>=p_n, such that {k-3, k-1} is not a pair of twin primes, where p_n=prime(n) and lpf = A020639.at n=29A243804Prime numbersat n=145406