42601
domain: N
Appears in sequences
- a(n) = (5*n + 1)^2 + 4*n + 1.at n=41A007533
- Prime(a(n)) + ... + prime(a(n)+3) is a square = A051395(n)^2.at n=31A072849
- Numbers k with the property that k followed by k 7's is prime.at n=12A133127
- The Wiener index of a chain of n triangles (i.e., joined like VVV..VV; here V is a triangle!).at n=38A143941
- Beach-Williams Pell numbers of type pqr (p,q,r primes).at n=3A212079
- Pseudoprimes to base 7, written in base 7.at n=17A262104
- Composite numbers k such that sum of proper divisors of k divides 2^k-1.at n=9A278315
- MM-numbers of labeled simple hypergraphs with no singletons spanning an initial interval of positive integers.at n=38A320463