4444444

Appears in sequences

• a(n) = 4*(10^n - 1)/9.at n=7A002278
• 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=32A045913
• Geometric mean of digits = 4 and digits are in nondecreasing order.at n=29A069518
• Nonsquarefree numbers obtained by repeating a single digit.at n=23A077572
• Integer part of the arithmetic mean of all the distinct numbers formed by permuting the digits of concatenation of numbers from 1 to n.at n=6A078266
• Repdigit Kaprekar numbers.at n=10A145875
• A109613(n)-fold concatenation of A008619(n).at n=6A180115
• Solutions y to x/SOD(x) = y, where x and y are palindromes.at n=16A276144
• 7-Kaprekar numbers.at n=2A333133
• Palindromic Kaprekar numbers.at n=10A382163