51243

Appears in sequences

• Number of compositions of n which are prime when concatenated and read as a decimal string.at n=19A116381
• a(n) = (7*11^n-1)/2.at n=4A199025
• a(n) = 2^n - A210109(n).at n=17A210145
• Numbers k such that phi(k) = phi'(k'), where phi(k) is the Euler totient function of k and k' is the arithmetic derivative of k.at n=6A260962
• Smallest c which can be split into positive integers a,b with a+b=c, such that a*b*c is divisible by each of the first n primes.at n=11A346970
• Integers m with k digits (for some k) that lie in an interval of k integers and the digits of m are the total number of distinct prime factors of all the integers in that interval.at n=13A348187