A238853 Right-truncatable, reversible primes in base 256.

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 773, 809, 823

Offset

1,1

Comments

See A238850 for definitions, and A238854 for comments on general context.

In base 256, there are 35127 such numbers (see A238855), shown here in decimal format. Base 256 is of interest to programmers because its digits correspond to 8-bit bytes and are easily readable in hexadecimal.

Links

Stanislav Sykora, Table of n, a(n) for n = 1..35127

Stanislav Sykora, PARI/GP scripts for genetic threads, with code and comments.

Example

The largest such number is 143496996325262301365903209731563 which, written in hex format, with hyphens between bytes for better readability, is 07-13-2F-CD-51-E1-B1-11-EB-23-CD-B3-15-EB. Truncate on the right any number of bytes and the remaining prefix is still a prime, no matter whether the bytes are read from left to right, or vice versa!

Prog

(PARI) See the link.

Crossrefs

Cf. All in base 10: A238850, 16: A238851, 100: A238852.

Cf. In base n: A238854 (largest), A238856 (maximum digits), A238857 (m-digits counts). Cf. A007500, A023107, A024770, A237600, A237601, A237602.

Sequence in context: A064555 A216887 A095320 * A077359 A057448 A049551

Adjacent sequences: A238850 A238851 A238852 * A238854 A238855 A238856

Keyword

nonn,fini,full,base

Author

Stanislav Sykora, Mar 06 2014

Status

approved