138388

Appears in sequences

• a(1)=2; for n > 1, a(n) = 2^(n-2) + (1/(2n-2)) * Sum_{ d divides n-1 } phi(2d)*2^((n-1)/d).at n=18A216957
• Discriminants of totally real cubic fields with 3 associated nonconjugate fields.at n=30A329787