78601domain: NAppears in sequencesNumber of 5-tuples of different integers from [ 2,n ] with no global factor.at n=26A015641Expansion of 1/((1-3x)(1-10x)(1-11x)).at n=4A018206a(n) is the coefficient of x^n in the polynomial given by Product_{k>=1} (1 + prime(k)*x^k).at n=18A147655