a(n) = 2^(n*(n-1)/2)*3^(n*(n+1)/2).A171739a(n) = 2^(n*(n-1)/2)*3^(n*(n+1)/2).Terms a(0) =1a(1) =3a(2) =54a(3) =5832a(4) =3779136a(5) =14693280768External referencesoeis: A171739