68683

Properties

Appears in sequences

• a(n) = Sum_{k=0..n-2} T(n,k) * T(n,k+2), with T given by A026725.at n=7A027209
• a(n) is the largest n-digit zeroless prime such that the sum of the two numbers that result from splitting a(n) between any two of its digits is a distinct prime.at n=3A103548
• Primes formed by concatenating k, k and 3 for k >= 1.at n=16A210512
• Inverse Euler transform of the Moebius function A008683.at n=36A320781
• Number of maximal subsets of {1..n} containing n such that every subset has a different sum.at n=43A325867
• Product_{n>=1} (1 + a(n)*x^n) = 1 + Sum_{n>=1} mu(n)*x^n, where mu = A008683.at n=36A353926
• Product_{n>=1} (1 + x^n)^a(n) = 1 + Sum_{n>=1} mu(n)*x^n, where mu = A008683.at n=36A353927
• Product_{n>=1} 1 / (1 - a(n)*x^n) = 1 + Sum_{n>=1} mu(n)*x^n, where mu = A008683.at n=36A353949
• Primes p such that if q is the next prime, the sum (with multiplicity) of prime factors of p^2 + q^2 is a square.at n=20A359443
• Primes having only {3, 6, 8} as digits.at n=26A385791
• Prime numbersat n=6826