1,1

Alois P. Heinz, Table of n, a(n) for n = 1..8000

E. Angelini, Vertices, edges, primes and non-primes, SeqFan list, Sept. 16, 2015.

Cf. A261297.

Sequence in context: A113419 A209940 A258096 * A133007 A141532 A197000

Adjacent sequences: A261295 A261296 A261297 * A261299 A261300 A261301

nonn

M. F. Hasler, Sep 16 2015

approved