91806
domain: N
Appears in sequences
- a(n) = C(n)*(C(n)-1)/2, where C(n) are the Catalan numbers (A000108).at n=7A051789
- Triangular numbers whose sum of prime factors (with repetition) is also triangular.at n=35A076169
- Triangular numbers all of whose digits are nonprimes.at n=40A111484
- Triangular numbers which are products of five distinct primes.at n=25A357590