OFFSET
1,1
COMMENTS
LINKS
Eric Weisstein's World of Mathematics, Consecutive Number Sequences
MATHEMATICA
k = 2; cc = oc = 0; lst = {}; While[k < 428, If[OddQ@k && !PrimeQ@k, cc = cc*10^IntegerLength@k + k; oc++; If[PrimeQ[cc], AppendTo[lst, oc]]; k++]; lst (* Robert G. Wilson v, Mar 18 2017 *)
Module[{nn=501, ocm}, ocm=Select[Range[9, nn, 2], CompositeQ]; Select[ Range[ Length[ ocm]], PrimeQ[FromDigits[Flatten[IntegerDigits/@Take[ocm, #]]]]&]] (* Harvey P. Dale, Sep 02 2022 *)
CROSSREFS
KEYWORD
base,nonn,bref,more
AUTHOR
XU Pingya, Mar 17 2017
STATUS
approved