368579domain: NPropertiesPrimalityPrimeyesAppears in sequencesPositions of non-crossing fixed-point-free involutions encoded by A014486 (after reflection) in A055089. Permutation of A064640.at n=26A064639Positions of non-crossing fixed-point-free involutions (encoded by A014486) in A055089, sorted to ascending order.at n=26A064640Prime numbersat n=31427