Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
Updated
Claims
1990_03_01_calkin: Calkin proves that the number of sum-free subsets of the first n integers is 2 to the n/2 + o(n), the displayed exponent form of Problem 748, in Bull. London Math. Soc. 22 (1990); refereed, not credited by the site's curator.
1991_06_01_alon: Alon proves, independently of Calkin, that the number of sum-free subsets of the first n integers is 2 to the n/2 + o(n), the displayed exponent form of Problem 748, in Israel J. Math. 73 (1991); refereed, not site-credited.
2003_01_01_sapozhenko: Sapozhenko proves, independently of Green, that the number of sum-free subsets of the first n integers is of order 2 to the n/2, with the same two-valued asymptotic; a Doklady note of 2003, in full in Discrete Math. 2008.
2003_04_04_green: Green proves that the number of sum-free subsets of the first n integers is asymptotically c(n) times 2 to the n/2, c(n) depending only on the parity of n, giving the asked exponent; refereed (Bull. LMS 2004), site-credited.