a(n) is the number of positive integers k for which Sum_{i=1..r} p_i = Sum_{i=1..r} e_i = n, where p_1^e_1*...*p_r^e_r is the canonical prime factorization of k.

A390784

a(n) is the number of positive integers k for which Sum_{i=1..r} p_i = Sum_{i=1..r} e_i = n, where p_1^e_1*...*p_r^e_r is the canonical prime factorization of k.

Terms

    a(0) =0a(1) =1a(2) =1a(3) =0a(4) =5a(5) =0a(6) =7a(7) =7a(8) =8a(9) =45a(10) =1a(11) =66a(12) =13a(13) =91a(14) =105a(15) =135a(16) =561a(17) =306a(18) =172a(19) =380a(20) =1540a(21) =462a(22) =3543a(23) =575a(24) =4624a(25) =3250a(26) =6175a(27) =21231a(28) =10963a(29) =24650

External references