The Janko group 
is one of the four Janko groups. It is a sporadic
group and simple group of group
order 
(Conway et al. 1985).
The group is implemented in the Wolfram Language as JankoGroupJ3[].
Janko Group J3
See also
Janko Groups, Simple Group, Sporadic GroupExplore with Wolfram|Alpha
References
Conway, J. H.; Curtis, R. T.; Norton, S. P.; Parker, R. A.; and Wilson, R. A. Atlas of Finite Groups: Maximal Subgroups and Ordinary Characters for Simple Groups. Oxford, England: Clarendon Press, 1985.Wilson, R. A. "ATLAS: Janko Group
."
https://brauer.maths.qmul.ac.uk/Atlas/v3/spor/J3/.Referenced on Wolfram|Alpha
Janko Group J3Cite this as:
Weisstein, Eric W. "Janko Group J3." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/JankoGroupJ3.html