Lonely non-twin primes: non-twins sandwiched between two pairs of twins.

Terms

a(0) =23a(1) =37a(2) =67a(3) =233a(4) =277a(5) =631a(6) =1039a(7) =1283a(8) =1297a(9) =1307a(10) =1613a(11) =1693a(12) =1709a(13) =2099a(14) =2137a(15) =2333a(16) =2719a(17) =2797a(18) =3271a(19) =3533a(20) =3547a(21) =3571a(22) =3923a(23) =4027a(24) =4253a(25) =4523a(26) =4643a(27) =4793a(28) =5483a(29) =5507