Numbers k such that 10^k + 7 is prime.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =9a(5) =24a(6) =60a(7) =110a(8) =134a(9) =222a(10) =412a(11) =700a(12) =999a(13) =1383a(14) =5076a(15) =5543a(16) =6344a(17) =14600a(18) =15093a(19) =21717a(20) =23636a(21) =30221a(22) =50711a(23) =221628a(24) =350071a(25) =371696a(26) =487291a(27) =995256a(28) =1043372