Number of occurrences of n as an entry in rows <= n of Pascal's triangle (A007318).

Terms

a(0) =0a(1) =3a(2) =1a(3) =2a(4) =2a(5) =2a(6) =3a(7) =2a(8) =2a(9) =2a(10) =4a(11) =2a(12) =2a(13) =2a(14) =2a(15) =4a(16) =2a(17) =2a(18) =2a(19) =2a(20) =3a(21) =4a(22) =2a(23) =2a(24) =2a(25) =2a(26) =2a(27) =2a(28) =4a(29) =2