30189

Appears in sequences

• a(n) is the smallest odd number that makes a(n)*2^N(n)-1 prime, where N(n) is the n-th Mersenne number that makes 2^N(n)-1 prime.at n=25A135434
• Products of 3 evil primes (A027699) p,q,r, such that numbers p*q, p*r, q*r, and p*q*r are odious (A000069).at n=32A230353
• a(0) = 1; a(n) = Sum_{k=0..floor(n/4)} binomial(n-3*k,k) * a(k).at n=31A352041