20002

Appears in sequences

• Numbers whose square is a palindrome.at n=26A002778
• a(0) = 1, a(n) = 32*n^2 + 2 for n > 0.at n=25A010021
• n written in fractional base 4/2.at n=34A024630
• Palindromes of form k*(k+9).at n=4A028571
• Numbers k such that k^2 is a palindrome with an odd number of digits.at n=25A028816
• Palindromes whose digits do not appear in previous term.at n=37A030285
• Lexicographically earliest strictly increasing base 3 autovarious sequence: a(n) = number of distinct a(k) mod 3^n (written in base 3).at n=21A037091
• Numbers n with property that n is a substring of its base 5 representation.at n=12A038105
• Base-10 palindromes that start with 2.at n=22A043037
• Composite palindromes whose sum of prime factors is palindromic (counted with multiplicity).at n=31A046354
• Length of hypotenuse squared in right triangle formed by a palindromic spiral plotted in Cartesian coordinates.at n=18A048871
• Numbers k such that k^3 has only even digits.at n=20A052004
• Palindromes whose square is a palindrome; also palindromes whose sum of squares of digits is less than 10.at n=20A057135
• Numbers k such that k^2 contains only digits {0,4,8}, not ending with zero.at n=7A058441
• Palindromes whose digit sum is 4.at n=8A065983
• Numbers n of the form k + reverse(k) for exactly two k.at n=38A072040
• To get a(n), write n in balanced ternary notation (using only digits -1, 0, 1, -1), then change -1's to 0's, 0's to 1's, and 1's to 2's.at n=43A072998
• Palindromic even numbers with an odd number of distinct prime factors.at n=21A075809
• Palindromic even numbers with exactly 3 prime factors (counted with multiplicity).at n=24A075816
• a(n) is the next available entirely straight or curved number, depending on whether n contains a straight digit or not.at n=39A079064