Mathematician Dan Brown Proves a Prime-Prefix-Free Sum Converges, Assuming the Riemann Hypothesis

The reciprocal sum of the prime-prefix-free numbers converges [pdf]

Dan Brown, author of The Da Vinci Code, proves that the sum of reciprocals of prime-prefix-free integers converges under the Riemann Hypothesis. The proof combines Selberg's theorem on primes in short intervals with an upper-bound sieve for prime pairs, and is machine-verified in Lean 4. The sum exceeds 3.5276 unconditionally and is bounded by about 5×10^14 under RH. Convergence hinges on 1/log 2 ≈ 1.4427 > 1, meaning base 2 is the only base where the analogous sum converges.

Convergence therefore hinges on 1/log 2 ≈ 1.4427 exceeding 1. In base b the same model gives the exponent 1/log b, below 1 for every b ≥ 3: binary is the one base in which the analogous sum is expected to converge.
  1. jdb1729

    The reciprocal sum of the prime-prefix-free numbers (https://oeis.org/A287117) converges to a number less than 5*10^14, conditional on the Riemann Hypothesis.

    This Lean-verified proof answers a question I posed 10 years ago: https://math.stackexchange.com/questions/2288648/does-the-su...

    An equivalent version: if we start with 1 and then output a stream of random bits, reading the number as a big-endian binary number at each step (so each time a bit arrives, the number is multiplied by 2 and 1 is either added or not), the expected time until the number is an odd prime is finite.

  2. dash2

    Why does it matter to hn? Is it because Dan Brown wrote it?

  3. yzydserd

    “Author of The Da Vinci Code”

    ?

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2026-10-09