292923domain: NAppears in sequencesNumbers n such that n divides 2^n + 1.at n=31A006521Pseudo-powers to base 3: numbers k that are not powers of 3 such that k divides 2^k + 1.at n=19A016057Composite numbers m such that (4^m - 2^m + 8*m^2 - 2) / (2*m*(2*m + 1)) is an integer.at n=11A235540