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A099663
a[n] is the largest prime before A002276[n] repdigits.
0
19, 211, 2221, 22193, 222199, 2222219, 22222199, 222222193, 2222222137, 22222222189, 222222222169, 2222222222197, 22222222222201, 222222222222151, 2222222222222203, 22222222222222153, 222222222222222221
OFFSET
2,1
EXAMPLE
n=2: 19 is before 22.
MATHEMATICA
<<NumberTheory`NumberTheoryFunctions` Table[Table[PreviousPrime[ *2(10^n-1)/9], {n, 2, 35}]
Drop[NextPrime[#, -1]&/@LinearRecurrence[{11, -10}, {0, 2}, 20], 2] (* Harvey P. Dale, Dec 19 2020 *)
KEYWORD
base,nonn
AUTHOR
Labos Elemer, Nov 17 2004
STATUS
approved