386760
domain: N
Appears in sequences
- Smith triangular numbers.at n=26A098840
- Triangular numbers that are sandwiched between two semiprimes; or triangular numbers t such that t-1 and t+1 are both semiprime.at n=33A121898
- Triangular numbers that are sums of twin prime pairs.at n=27A165966
- a(n) = 1*3*5 + 3*5*7 + 5*7*9 + ... (n terms).at n=20A196506
- Triangular numbers that are sandwiched between two squarefree semiprimes.at n=31A375384