44621

Properties

Appears in sequences

• a(n) = [ 1/(2*t(n+1) - t(n) - t(n+2)) ], where t(n) = tan(Pi/2 - 1/n) satisfies n-1 < t(n) < n for all n >= 1.at n=29A024817
• Primes of the form 666*k - 1.at n=21A063472
• a(n) is the smallest lesser of twin prime p, such that prime(2 + p) - prime(p) = 2n (cf. A096474).at n=26A096475
• Primes p of Erdos-Selfridge class 4+ with largest prime factor of p+1 not of class 3+.at n=33A129472
• Primes of the form p^2+100, where p is prime.at n=24A182476
• a(n) = prime(prime(n^2)).at n=24A217623
• The prime numbers that are prime-indexed primes and whose digit sum, adjacent digit sum concatenation, and adjacent digit difference concatenation are also primes.at n=8A331031
• Triangle read by rows: T(n,k) is the number of weakly connected acyclic digraphs on n unlabeled nodes with k arcs, n >= 1, k = 0..(n-1)*n/2.at n=53A350449
• Lesser of twin self primes, i.e., smaller member of the pair of self primes differing by 2.at n=5A380713
• Prime numbersat n=4637