118901521

Appears in sequences

• Carmichael numbers of the form (6*k+1)*(12*k+1)*(18*k+1), where 6*k+1, 12*k+1 and 18*k+1 are all primes.at n=3A033502
• Carmichael numbers of the form C = (30n-p)*(60n-(2p+1))*(90n-(3p+2)), where n is a natural number and p, 2p+1, 3p+2 are all three prime numbers.at n=6A182087
• Carmichael numbers k that satisfy 2^d == 2^(k/d) (mod k) for all d|k and are not Super-Poulet numbers (A050217).at n=4A291612
• Carmichael numbers k such that 2^d == 2^(k/d) (mod k) for all d|k.at n=5A291616
• Carmichael numbers whose prime factors form an arithmetic progression.at n=10A300949
• Numbers of the form: (6*m + 1) * (12*m + 1) * Product_{i=1..k-2} (9 * 2^i * m + 1), where k >= 3, with the condition that each of the factors is prime and that m is divisible by 2^(k-4).at n=4A317126
• Imprimitive Carmichael numbers: Carmichael numbers m such that if m = p_1 * p_2 * ... *p_k is the prime factorization of m then g(m) = gcd(p_1 - 1, ..., p_k - 1) > sqrt(lambda(m)), where lambda is the Carmichael lambda function (A002322).at n=26A328935
• Carmichael numbers (A002997) that are not minimal in their family.at n=13A335584
• Carmichael numbers k for which the 2-adic valuation of phi(k) does not exceed the 2-adic valuation of k-1.at n=18A339818
• a(n) is the numerator of the squared circumradius of a cyclic quadrilateral with sides n, n+1, n+2, n+3.at n=26A351696