538461

Appears in sequences

• Kaprekar numbers: numbers k such that k = q + r and k^2 = q*10^m + r, for some m >= 1, q >= 0 and 0 <= r < 10^m. Here q and r must both have the same number of digits.at n=21A045913
• The full list of 6-Kaprekar numbers.at n=18A053397
• Another version of the Kaprekar numbers (A006886): n such that n = q+r and n^2 = q*10^m+r, for some m >= 1, q >= 0 and 0 <= r < 10^m, with n != 10^a, a >= 1 and n an m-digit number.at n=36A053816
• Square roots of terms in A238237.at n=25A290449
• Numbers that have exactly 9 representations as a k-gonal number, P(n,k) = n*((k-2)*n - (k-4))/2, k and n >= 3.at n=6A321159
• Kaprekar numbers (A006886) that are divisible by the sum of their digits.at n=16A382165
• Irregular table, read by rows, where row z = 2, 3, 4, ... lists pairs (y, x) such that x + y/z = concat(y, x)/z with 0 < y < z, gcd(y, z) = 1, and primitive x, cf. comments.at n=53A383188