A083535 A version of the Chebyshev function theta(n): a(n) = ceiling(Sum_{primes p <= n } log(p)).

0, 1, 2, 2, 4, 4, 6, 6, 6, 6, 8, 8, 11, 11, 11, 11, 14, 14, 17, 17, 17, 17, 20, 20, 20, 20, 20, 20, 23, 23, 27, 27, 27, 27, 27, 27, 30, 30, 30, 30, 34, 34, 38, 38, 38, 38, 41, 41, 41, 41, 41, 41, 45, 45, 45, 45, 45, 45, 50, 50, 54, 54, 54, 54, 54, 54, 58, 58, 58, 58, 62, 62, 66, 66, 66, 66