1,2

It is a strong conjecture that 2*prime(n) appears in A336957 for all n>1, and it is known that 4 does not appear.

See also the comment in A336957 discussing when primes first appear in A336957.

N. J. A. Sloane, Table of n, a(n) for n = 1..20000

N. J. A. Sloane, Table comparing the present sequence and A338074

A336957(14) = 22 = 2*prime(5), so a(5) = 14.

Cf. A336957, A337276, A338074.

Sequence in context: A275741 A244846 A210415 * A087397 A210414 A289832

Adjacent sequences: A337272 A337273 A337274 * A337276 A337277 A337278

sign

N. J. A. Sloane, Sep 09 2020

approved