A145671 a(n) = number of components of the graph P(n,3) (defined in Comments).

1, 2, 4, 8, 15, 32, 88, 209, 539, 1403, 3698, 9962, 26447, 71579, 196590, 541473, 1501720, 4186566, 11737617

Offset

1,2

Comments

Let H(n,b) be the Hamming graph whose vertices are the sequences of length n over the alphabet {0,1,...,b-1} with adjacency being defined by having Hamming distance 1. Let P(n,b) be the subgraph of H(n,b) induced by the set of vertices which are base b representations of primes with n digits (not allowing leading 0 digits).

Links

Table of n, a(n) for n=1..19.

Crossrefs

Cf. A145667-A145674.

Sequence in context: A227236 A061030 A036661 * A316522 A317712 A108693

Adjacent sequences: A145668 A145669 A145670 * A145672 A145673 A145674

Keyword

nonn,base,more

Author

W. Edwin Clark, Mar 17 2009

Extensions

a(11)-a(19) from Max Alekseyev, May 12 2011

Status

approved