Numbers n such that 1+2n+3n^2 is a triangular number.
A122513
Numbers n such that 1+2n+3n^2 is a triangular number.
Terms
- a(0) =0a(1) =1a(2) =46a(3) =135a(4) =4540a(5) =13261a(6) =444906a(7) =1299475a(8) =43596280a(9) =127335321a(10) =4271990566a(11) =12477562015a(12) =418611479220
External references
- oeis: A122513