Numbers k such that k and 10*k are both triangular numbers.
A068085
Numbers k such that k and 10*k are both triangular numbers.
Terms
- a(0) =0a(1) =1a(2) =21a(3) =78a(4) =1540a(5) =30381a(6) =112575a(7) =2220778a(8) =43809480a(9) =162333171a(10) =3202360435a(11) =63173239878a(12) =234084320106
External references
- oeis: A068085