A048661 Number of n-digit dihedral primes for which the 4 numbers (n, n upside-down, n in a mirror, n upside-down and mirrored) are distinct.

0, 0, 0, 0, 0, 4, 12, 16, 132, 308, 1096, 3704, 12984, 47008

Offset

1,6

Links

Table of n, a(n) for n=1..14.

Carlos Rivera, Puzzle 39. The Mirrorable Numbers (By Mike Keith), The Prime Puzzles and Problems Connection.

Crossrefs

Cf. A134996.

Sequence in context: A066632 A038242 A370191 * A036047 A356812 A045042

Adjacent sequences: A048658 A048659 A048660 * A048662 A048663 A048664

Keyword

base,more,nonn

Author

Felice Russo

Extensions

a(11)-a(14) from Sean A. Irvine, Jun 25 2021

Status

approved