

A238856


Number of digits of the largest righttruncatable reversible prime in base n.


8



0, 3, 3, 4, 3, 4, 5, 4, 4, 6, 4, 6, 6, 6, 6, 5, 4, 7, 6, 7, 5, 6, 5, 8, 6, 6, 6, 6, 7, 7, 6, 6, 8, 6, 8, 7, 8, 8, 7, 8, 7, 8, 8, 8, 8, 7, 7, 9, 9, 8, 7, 8, 10, 10, 9, 8, 6, 9, 8, 7, 9, 9, 9, 9, 11, 8, 7, 9, 10, 9, 10, 9, 9, 11, 10, 10, 9, 9, 8, 9, 9, 8, 10, 10, 10, 9, 9, 9, 10, 11
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OFFSET

2,2


COMMENTS

For definitions and more comments, see A238854 and A238850. A weak conjecture: this sequence might be bounded.


LINKS

Stanislav Sykora, Table of n, a(n) for n = 2..390
Stanislav Sykora, PARI/GP scripts for genetic threads, with code and comments.


EXAMPLE

a(16) = 6 because the largest truncatable reversible prime in base 16 has 6 hexadecimal digits (see A238851).


PROG

(PARI) See the link.


CROSSREFS

Cf. Full in base 10: A238850, 16: A238851, 100: A238852, 256: A238853.
Cf. In base n: A238854 (largest), A238855 (totals), A238857 (mdigit counts).
Cf. A007500, A023107, A024770, A237600, A237601, A237602.
Sequence in context: A216190 A267592 A243341 * A096139 A175928 A161357
Adjacent sequences: A238853 A238854 A238855 * A238857 A238858 A238859


KEYWORD

nonn,base,hard


AUTHOR

Stanislav Sykora, Mar 13 2014


STATUS

approved



