2117473

Appears in sequences

• a(n) = a(n-1) + 3*a(n-2) for n > 1, a(0) = a(1) = 1.at n=18A006130
• For n>0, a(n) is the least quasi-Carmichael number to base -n, extended to n=0 with the least composite squarefree integer.at n=20A029591
• a(n) = 3*a(n-2) - a(n-1) for n > 1, a(0) = 0, a(1) = 1.at n=19A182228