A238857 Array read by rows: row n lists total number of m-digit right-truncatable reversible primes in base n.

0, 1, 1, 1, 0, 2, 1, 1, 0, 2, 4, 4, 2, 0, 3, 1, 1, 0, 3, 5, 3, 1, 0, 4, 7, 7, 5, 1, 0, 4, 5, 5, 3, 0, 4, 5, 6, 1, 0, 4, 8, 7, 9, 4, 1, 0, 5, 5, 7, 5, 0, 5, 10, 8, 4, 1, 1, 0, 6, 11, 17, 12, 3, 1, 0, 6, 11, 13, 6, 2, 1, 0, 6, 9, 11, 9, 4, 1, 0, 6, 13, 12, 7, 1, 0, 7, 9, 7, 1, 0

Offset: 2

Author

Stanislav Sykora, Mar 13 2014

Keywords

• nonn
• tabf
• base

Comments

For definitions and more comments, see A238854 and A238850.

This is an irregular table with one line for every base, starting at 2, while the columns correspond to the number of digits (1,2,3,...). Each row terminates with a zero (in any given base there appears to be a finite number of instances).

Examples

			These are the first rows of the table:
   2: 0,
   3: 1, 1, 1, 0,
   4: 2, 1, 1, 0,
   5: 2, 4, 4, 2, 0,
   6: 3, 1, 1, 0,
   7: 3, 5, 3, 1, 0,
   8: 4, 7, 7, 5, 1, 0,
   9: 4, 5, 5, 3, 0,
  10: 4, 5, 6, 1, 0,
  ...
Hence, there are 6 right truncatable reversible primes with 3 digits in base 10 (see A238850).
		

Links

• Stanislav Sykora, Table of n, a(n) for n = 2..5071
• Stanislav Sykora, PARI/GP scripts for genetic threads, with code and comments.

Crossrefs

Full in base 10: A238850, 16: A238851, 100: A238852, 256: A238853.

In base n: A238854 (largest), A238855 (totals), A238856 (maximum digits).

Cf. A007500, A023107, A024770, A237600, A237601, A237602.

Programs

PARI

See the link.