1,12

(1) Conjecture: a(n) > 0 for n >= 11.

(2) Conjecture: A278287(n) > 0 for n >= 11.

Conjecture (1) and conjecture (2) are first and second parts of Goldbach-like conjecture in A001031.

Table of n, a(n) for n=1..110.

a(12) = 2 because 4*(12-0-1)+3 = 47 and 4*0+3 = 3 are primes where 3 < 12 and 4*(12-1-1)+3 = 43 and 4*1+3 = 7 are primes where 7 < 12.

Cf. A001031, A002144, A278287.

Sequence in context: A237112 A238013 A303940 * A143488 A201159 A047070

Adjacent sequences: A280131 A280132 A280133 * A280135 A280136 A280137

nonn

Juri-Stepan Gerasimov, Dec 26 2016

approved