Divide primes in groups with 2n elements and add together.

Terms

a(0) =0a(1) =5a(2) =36a(3) =156a(4) =442a(5) =954a(6) =1854a(7) =3154a(8) =4998a(9) =7514a(10) =10784a(11) =14786a(12) =19932a(13) =26148a(14) =33448a(15) =42340a(16) =52208a(17) =64322a(18) =77898a(19) =93116a(20) =110224a(21) =129978a(22) =151990a(23) =175224a(24) =201584a(25) =231272a(26) =263500a(27) =298590a(28) =335856a(29) =376616