Number of 6-element subsets of [n] having a prime element sum.

Terms

a(0) =0a(1) =1a(2) =7a(3) =20a(4) =51a(5) =117a(6) =239a(7) =430a(8) =724a(9) =1163a(10) =1834a(11) =2823a(12) =4252a(13) =6226a(14) =8870a(15) =12299a(16) =16712a(17) =22340a(18) =29524a(19) =38606a(20) =49979a(21) =63965a(22) =80946a(23) =101250a(24) =125316a(25) =153592a(26) =186694a(27) =225268a(28) =270172a(29) =322285