Triangular numbers whose sum of primes from smallest to largest prime factor is triangular and whose sum of composites from smallest to largest prime factor is triangular.
A076207
Triangular numbers whose sum of primes from smallest to largest prime factor is triangular and whose sum of composites from smallest to largest prime factor is triangular.
Terms
- a(0) =3a(1) =21a(2) =105a(3) =325a(4) =7875a(5) =9568125
External references
- oeis: A076207