Positive triangular numbers (A000217) that are hexagonal numbers (A000384) divided by 2.
A259157
Positive triangular numbers (A000217) that are hexagonal numbers (A000384) divided by 2.
Terms
- a(0) =3a(1) =3570a(2) =4119885a(3) =4754343828
External references
- oeis: A259157