20121
domain: N
Appears in sequences
- Let C(n) = product of composite numbers between the n-th prime and (n+1)-th prime; a(n) = floor(C(n+1)/C(n)).at n=29A073836
- 4-Smith numbers.at n=18A103125
- Ternary emirpimes.at n=14A119684
- Number of 2 X 2 matrices with all elements in {-n,..,0,..,n} with permanent = determinant * n.at n=33A280407
- Numbers k such that k![4] - 32 is prime, where k![4] = A007662(k) = quadruple factorial.at n=27A329167