Number of 3's in n-th term of A022470.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =1a(5) =1a(6) =2a(7) =3a(8) =3a(9) =6a(10) =7a(11) =7a(12) =11a(13) =15a(14) =14a(15) =24a(16) =30a(17) =38a(18) =48a(19) =73a(20) =83a(21) =114a(22) =155a(23) =191a(24) =251a(25) =336a(26) =426a(27) =560a(28) =737a(29) =964