a(n) = A016755(n) - A001845(n).

Terms

a(0) =0a(1) =20a(2) =100a(3) =280a(4) =600a(5) =1100a(6) =1820a(7) =2800a(8) =4080a(9) =5700a(10) =7700a(11) =10120a(12) =13000a(13) =16380a(14) =20300a(15) =24800a(16) =29920a(17) =35700a(18) =42180a(19) =49400a(20) =57400a(21) =66220a(22) =75900a(23) =86480a(24) =98000a(25) =110500a(26) =124020a(27) =138600a(28) =154280a(29) =171100