Sum of digits of zero-absent composite a(n) equals number of prime factors.

A050690

Sum of digits of zero-absent composite a(n) equals number of prime factors.

Terms

    a(0) =12a(1) =32a(2) =1152a(3) =11232a(4) =13122a(5) =14112a(6) =21312a(7) =111132a(8) =112112a(9) =3121152a(10) =11231232a(11) =11354112a(12) =812122112a(13) =1251213312a(14) =2211121152a(15) =2211213312a(16) =5121114112a(17) =26122125312a(18) =56321114112a(19) =62214111232a(20) =431711322112

External references