Carl Severin Wigert

Carl Severin Wigert (1871–1941) was a Swedish mathematician who created Stieltjes–Wigert polynomials and worked on the divisor function, including correctly describing its maximal order of growth. Wigert proved that

${\displaystyle \limsup _{n\to \infty }{\frac {\log d(n)}{\log n/\log \log n}}=\log 2.}$