Semiprimes that are not the sum of 3 pentagonal numbers.

Terms

a(0) =4a(1) =9a(2) =21a(3) =26a(4) =33a(5) =38a(6) =55a(7) =65a(8) =77a(9) =111a(10) =142a(11) =159a(12) =166a(13) =183a(14) =205a(15) =217a(16) =226a(17) =265a(18) =346a(19) =371a(20) =395a(21) =417a(22) =453a(23) =551a(24) =573a(25) =597a(26) =655a(27) =681a(28) =843a(29) =905