Pentagonal numbers with prime indices.

Terms

a(0) =5a(1) =12a(2) =35a(3) =70a(4) =176a(5) =247a(6) =425a(7) =532a(8) =782a(9) =1247a(10) =1426a(11) =2035a(12) =2501a(13) =2752a(14) =3290a(15) =4187a(16) =5192a(17) =5551a(18) =6700a(19) =7526a(20) =7957a(21) =9322a(22) =10292a(23) =11837a(24) =14065a(25) =15251a(26) =15862a(27) =17120a(28) =17767a(29) =19097