Increasing sequence obtained by union of two sequences {b(n)} and {c(n)}, where b(n) is the smallest odd composite number m such that both m-2 and m+2 are prime and the set of distinct prime factors of m consists of the first n odd primes and c(n) is the smallest composite number m such that both m-1 and m+1 are primes and the set of the distinct prime factors of m consists of the first n primes.
A136358
Increasing sequence obtained by union of two sequences {b(n)} and {c(n)}, where b(n) is the smallest odd composite number m such that both m-2 and m+2 are prime and the set of distinct prime factors of m consists of the first n odd primes and c(n) is the smallest composite number m such that both m-1 and m+1 are primes and the set of the distinct prime factors of m consists of the first n primes.
Terms
- a(0) =4a(1) =6a(2) =9a(3) =15a(4) =30a(5) =105a(6) =420a(7) =2310a(8) =3465a(9) =15015a(10) =180180a(11) =765765a(12) =4084080a(13) =106696590a(14) =247342095a(15) =892371480a(16) =3011753745a(17) =9704539845a(18) =100280245065a(19) =103515091680
External references
- oeis: A136358