165710domain: NAppears in sequencesNumbers k that divide the alternating sum phi(1) - phi(2) + phi(3) - phi(4) + ... + ((-1)^(k+1))*phi(k).at n=19A067929Solutions to A096509[x]=7; number of prime-powers [including primes] in the neighborhood of x with Ceiling[Log[x]] radius equals 7.at n=19A096518