179992922domain: NAppears in sequencesNumbers k such that prime(k) == 1 (mod k).at n=27A023143Numbers k that divide the average of prime(k-1) and prime(k+1).at n=17A066828Numbers k such that prime(k+1) == 5 (mod k).at n=27A105329Integers n such that prime(n-1) + prime(n+1) is a multiple of n.at n=27A260989