Finite almost simple 4-primary groups with connected Gruenberg-Kegel graph

Let G be a finite group. Denote by pi(G) the set of prime divisors of the order of G. The Gruenberg-Kegel graph (prime graph) of G is the graph with the vertex set pi(G) in which two different vertices p and q are adjacent if and only if G has an element of order pq. If vertical bar pi(G)vertical bar = n, then the group G is called n-primary. In 2011, A.S. Kondrat'ev and I.V. Khramtsov described finite almost simple 4-primary groups with disconnected Gruenberg-Kegel graph. In the present paper we describe finite almost simple 4-primary groups with connected Gruenberg-Kegel graph. For each of these groups, its Gruenberg-Kegel graph is found. The results are presented in a table. According to the table, there are 32 such groups. The results are obtained with the use of the computer system GAP.