76283domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumerator of Sum_{k=1..n} 1/phi(k).at n=34A028415Number of planar polyhexes with n cells and a single hole of size at least 2.at n=13A038140Primes of the form k^2 + prime(k) + 1.at n=20A063461Pierce expansion of log(2).at n=17A091846Prime numbersat n=7508