100376domain: NAppears in sequencesNumbers m such that m^2 can be obtained from m by inserting an internal block of (contiguous) digits.at n=33A045953Numbers k such that k^2 can be obtained from k by inserting a block of digits.at n=41A046838Concatenation of first 3 digits and last 3 digits of n-th perfect number.at n=24A138877