Integers with missing digits;
Harmonic series;
SUBSUMS;
D O I:
10.1007/s11139-021-00444-5
中图分类号:
O1 [数学];
学科分类号:
0701 ;
070101 ;
摘要:
A classical theorem of Kempner states that the sum of the reciprocals of positive integers with missing decimal digits converges. This result is extended to much larger families of "missing digits" sets of positive integers with convergent harmonic series.