Total number of parts in all compositions of n with at least two parts in increasing order.

Terms

a(0) =0a(1) =0a(2) =0a(3) =2a(4) =8a(5) =28a(6) =77a(7) =202a(8) =490a(9) =1152a(10) =2624a(11) =5869a(12) =12913a(13) =28116a(14) =60660a(15) =130004a(16) =277065a(17) =587859a(18) =1242540a(19) =2617942a(20) =5500394a(21) =11528284a(22) =24109349a(23) =50321442a(24) =104844426a(25) =218086957a(26) =452963310a(27) =939496802a(28) =1946122511a(29) =4026488387