A281529 a(n) = least denominator Y of any proper fraction X/Y which needs n or more terms to be written as a signed sum of distinct unit fractions.
2, 3, 7, 23, 163
Offset: 1
References
- W. Sierpiński, O rozkładach liczb wymiernych na ułamki proste, PWN, Warsaw, Poland, 1957, pp. 96-100.