Number of decimal digit 1's in A006937(n).

Terms

a(0) =1a(1) =2a(2) =7a(3) =14a(4) =44a(5) =158a(6) =535a(7) =1821a(8) =6092a(9) =20000a(10) =66378a(11) =220957a(12) =733556a(13) =2436430a(14) =8095687a(15) =26892148a(16) =89338832a(17) =296769545a(18) =985760656a(19) =3274702309a(20) =10878267642a(21) =36136741115