Least m>0 for which m*n^2 + 1 is a square and m*triangular(n) + 1 is a triangular number (A000217). Or -1 if no such m exists.
A267077
Least m>0 for which m*n^2 + 1 is a square and m*triangular(n) + 1 is a triangular number (A000217). Or -1 if no such m exists.
Terms
- a(0) =1a(1) =35a(2) =30a(3) =18135a(4) =189a(5) =27a(6) =321300a(7) =23760a(8) =1188585957a(9) =1656083a(10) =26a(11) =244894427400a(14) =86478a(18) =26780050a(20) =274554988002
External references
- oeis: A267077