Number of n-element subsets of [2n] having a prime element sum.

Terms

a(0) =0a(1) =1a(2) =4a(3) =6a(4) =21a(5) =59a(6) =239a(7) =760a(8) =2970a(9) =10060a(10) =38930a(11) =124735a(12) =503767a(13) =1986024a(14) =7059818a(15) =27806989a(16) =107739266a(17) =376458328a(18) =1421570461a(19) =5750402871a(20) =23095812036a(21) =89360066340a(22) =315720338715