Number of prime parts, counted without multiplicity, in all compositions of n.

Terms

a(0) =0a(1) =0a(2) =1a(3) =3a(4) =6a(5) =15a(6) =33a(7) =74a(8) =160a(9) =344a(10) =731a(11) =1544a(12) =3237a(13) =6753a(14) =14022a(15) =29009a(16) =59819a(17) =123010a(18) =252341a(19) =516560a(20) =1055476a(21) =2153115a(22) =4385889a(23) =8922556a(24) =18131000a(25) =36805009a(26) =74643126a(27) =151255021a(28) =306267833a(29) =619719217