69649

Appears in sequences

• a(n) = (5*n^2 + 1)*n^2 / 6.at n=17A008354
• Strong pseudoprimes to base 65.at n=31A020291
• a(n) = A027113(n, 2n-3).at n=10A027121
• Numbers k such that k^2 is palindromic in base 16.at n=29A029733
• Numbers k such that k^3 is palindromic in base 16.at n=10A029735
• a(1) = 1, a(2n) = 16a(n), a(2n+1) = a(2n)+1.at n=27A033052
• Main diagonal of Family 1 "Rule 90 x Rule 150" array.at n=4A048709
• 24 'Reverse and Add' steps are needed to reach a palindrome.at n=42A065318
• Long leg of primitive Pythagorean triangles having legs that add up to a square, sorted on hypotenuse.at n=36A089548
• Numbers such that all subsets of {prime(a(1)), ..., prime(a(n))} have a different sum.at n=19A138856
• Number of days after Jan 01 1000 such that the date written in the ISO-8601-format YYYYMMDD is palindromic.at n=23A210883
• Numbers k such that 2^psi(k) == -1 (mod k) where psi(k) = A001615(k).at n=9A291164
• Numbers in base 10 that are palindromic in bases 2, 4, and 16.at n=27A319583
• Numbers that are palindromic in base i-1.at n=30A342725