User blog comment:Natan Consigli/Definition of k-torials/@comment-1605058-20150826183009/@comment-26930274-20150826222500

You're right. This would fix the problem: a[n]b= b+1 for n<1 or a[n]b= a[n-1]a[n](b-1) otherwise. Or equivalently: a[n]b= b+1 for n<1, a[1]b = a+b or a[n]b = a[n-1]a...[n-1]a with a occurring b times otherwise. The a(4) of the oeis sequence which is the 4th term of the pentatorial sequence