Number of partitions of 4n with equal sums of odd and even parts.

Terms

a(0) =1a(1) =1a(2) =4a(3) =12a(4) =30a(5) =70a(6) =165a(7) =330a(8) =704a(9) =1380a(10) =2688a(11) =4984a(12) =9394a(13) =16665a(14) =29970a(15) =52096a(16) =90090a(17) =152064a(18) =257180a(19) =423360a(20) =697851a(21) =1129392a(22) =1819632a(23) =2891520a(24) =4583250a(25) =7162364a(26) =11161752a(27) =17211180a(28) =26427544a(29) =40208520