login
a(n) = size of the n-th term in S(10) (defined in Comments).
1

%I #7 Jul 25 2019 07:18:56

%S 4,21,143,1061,8363,68900,1,1,1,1,1,1,586044,1,1,1,1,1,1,1,1,1,1,1,1,

%T 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1

%N a(n) = size of the n-th term in S(10) (defined in Comments).

%C Let H(L,b) be the Hamming graph whose vertices are the sequences of length L over the alphabet {0,1,...,b-1} with adjacency being defined by having Hamming distance 1. Let P(L,b) be the subgraph of H(L,b) induced by the set of vertices which are base b representations of primes with L digits (not allowing leading 0 digits). Let S(b) be the sequence of all components of the graphs P(L,b), L>0, sorted by the smallest prime in a component.

%Y Cf. A006879, A158576, A158578, A158579 (base 10).

%Y Cf. A145667, A145668, A145669, A145670 (base 2).

%Y Cf. A145671, A145672, A145673, A145674 (base 3).

%K base,hard,more,nonn

%O 1,1

%A _W. Edwin Clark_, Mar 21 2009