Find smallest pair (x,y) such that x^2 - y^2 = 11...1 (n times) = (10^n-1)/9; sequence gives value of x.

A048611

Find smallest pair (x,y) such that x^2 - y^2 = 11...1 (n times) = (10^n-1)/9; sequence gives value of x.

Terms

    a(0) =1a(1) =6a(2) =20a(3) =56a(4) =156a(5) =340a(6) =2444a(7) =4440a(8) =167000a(9) =55556a(10) =267444a(11) =333400a(12) =132687920a(13) =5555556a(14) =10731400a(15) =40938800a(16) =2682647040a(17) =333334000a(19) =3334367856a(20) =11034444280a(21) =35595935980

External references