101440

Appears in sequences

• Expansion of e.g.f. tan(arctanh(x) + log(x+1)).at n=7A013158
• Positive numbers k such that k and 4*k are anagrams in base 6 (written in base 6).at n=6A023066
• Sum of the numbers in the trajectory of n for the 3x+1 problem.at n=26A033493
• Record sum of numbers in trajectory of 3x+1 problem.at n=7A033494
• Ulam's conjecture (steps to return n to 1 after division by 2 and, if needed, multiplication by 3 with 1 added).at n=26A049074
• The Wiener index of a chain of n squares joined at vertices (i.e., joined like <><><>...<>; here <> is a square!).at n=31A143943
• a(1)=0; thereafter a(2k)=k+a(k), a(2k+1)=6k+4+a(6k+4).at n=53A270814