Odd numbers that are the concatenation of a prime p and the p-th nonprime nonnegative integer.

Terms

a(0) =21a(1) =1725a(2) =1927a(3) =2333a(4) =3751a(5) =79105a(6) =83111a(7) =131169a(8) =167213a(9) =173219a(10) =191243a(11) =193245a(12) =197249a(13) =227287a(14) =229289a(15) =251315a(16) =269335a(17) =307381a(18) =317393a(19) =367453a(20) =379469a(21) =383473a(22) =397489a(23) =419515a(24) =421517a(25) =431529a(26) =433531a(27) =439537a(28) =449549a(29) =463565