Triangular numbers that are 5 times another triangular number.
A077261
Triangular numbers that are 5 times another triangular number.
Terms
- a(0) =0a(1) =15a(2) =105a(3) =4950a(4) =33930a(5) =1594005a(6) =10925475a(7) =513264780a(8) =3517969140a(9) =165269665275
External references
- oeis: A077261