Second crank moment minus second rank moment: M_2(n) - N_2(n) = 2*spt(n).

Terms

a(0) =2a(1) =6a(2) =10a(3) =20a(4) =28a(5) =52a(6) =70a(7) =114a(8) =160a(9) =238a(10) =322a(11) =476a(12) =630a(13) =880a(14) =1178a(15) =1602a(16) =2096a(17) =2814a(18) =3640a(19) =4798a(20) =6174a(21) =7996a(22) =10184a(23) =13090a(24) =16526a(25) =20972a(26) =26330a(27) =33124a(28) =41260a(29) =51546