221185

Appears in sequences

• First occurrence of n consecutive numbers that take same number of steps to reach 1 in 3x+1 problem.at n=23A000546
• a(n) = T(8,n), array T given by A048472.at n=12A048480
• Pierpont 3-almost primes. 3-almost primes of form (2^K)*(3^L)+1.at n=19A112797
• a(n) = n*(n+1)*(3*n^2+5*n+4)/12.at n=30A176060