39229

Properties

Appears in sequences

• a(n) is the number of integers m which take n steps to reach 1 in '3x+1' problem.at n=47A005186
• a(n) = floor( n*(n-1)*(n-2)*(n-3)/22 ).at n=32A011932
• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 79.at n=0A031667
• Let (p1,p2), (p3,p4) be pairs of twin primes with p1*p2=p3+p4-1; sequence gives values of p2.at n=27A047977
• a(n) is the smallest number m such that m! is divisible by the left factorial !n (A003422).at n=13A062549
• Primes that belong to A156781, A156782 and A156783.at n=2A156785
• Primes of the form k^2 + 25.at n=41A346145
• Prime numbersat n=4131