A115445 Numbers whose square is the concatenation of two numbers k and k-7.
9, 13, 3656545, 4565636, 5434365, 6343456, 3646962589704198389, 6353037410295801612, 9101508044249652935, 7903999111431765764698711045778, 9722180929613583946516892863960
Offset: 1
Examples
4023943_4023936 = 6343456^2.