login
Number of all right-truncatable reversible primes in base n.
8

%I #16 Dec 21 2015 14:11:47

%S 0,3,4,12,5,12,24,17,16,33,22,29,50,39,40,39,24,65,80,100,58,58,69,

%T 122,101,90,83,125,114,133,114,122,255,203,252,123,152,221,202,308,

%U 131,250,299,397,303,143,201,484,497,423,269,253,442,944,845,378,231,460,420,455,538,438

%N Number of all right-truncatable reversible primes in base n.

%C For definitions and more comments, see A238854 and A238850.

%C Conjecture: in any base n, the number of right-truncatable reversible primes is finite.

%H Stanislav Sykora, <a href="/A238855/b238855.txt">Table of n, a(n) for n = 2..390</a>

%H Stanislav Sykora, <a href="https://oeis.org/wiki/File:GeneticThreads.txt">PARI/GP scripts for genetic threads</a>, with code and comments

%e In bases 10, 16, 100, and 256 (used as examples in the crossrefs) there are, respectively, 16, 40, 1552, and 35127 such numbers.

%o (PARI) See the link.

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

%Y Cf. In base n: A238854 (largest), A238856 (maximum digits), A238857 (m-digit counts).

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

%K nonn,base

%O 2,2

%A _Stanislav Sykora_, Mar 07 2014