Comparisons needed for Batcher's sorting algorithm applied to 2^n items.

Terms

a(0) =0a(1) =1a(2) =5a(3) =19a(4) =63a(5) =191a(6) =543a(7) =1471a(8) =3839a(9) =9727a(10) =24063a(11) =58367a(12) =139263a(13) =327679a(14) =761855a(15) =1753087a(16) =3997695a(17) =9043967a(18) =20316159a(19) =45350911a(20) =100663295a(21) =222298111a(22) =488636415a(23) =1069547519a(24) =2332033023a(25) =5066719231a(26) =10972299263a(27) =23689428991a(28) =51002736639a(29) =109521666047