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A099664 a[n] is the largest prime before A002278[n] repdigits. 1
3, 43, 443, 4441, 44417, 444443, 4444409, 44444399, 444444443, 4444444429, 44444444441, 444444444443, 4444444444439, 44444444444353, 444444444444421, 4444444444444423, 44444444444444411, 444444444444444419 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

n=2: 43 is before 44.

MATHEMATICA

<<NumberTheory`NumberTheoryFunctions` Table[Table[PreviousPrime[4*(10^n-1)/9], {n, 1, 35}]

Table[NextPrime[FromDigits[PadRight[{}, n, 4]], -1], {n, 20}] (* Harvey P. Dale, Feb 25 2013 *)

CROSSREFS

Cf. A003618, A003617, A096497, A096498, A068104, A002275-A002283, A099656-A099668.

Sequence in context: A020461 A138974 A036940 * A173770 A093163 A199020

Adjacent sequences:  A099661 A099662 A099663 * A099665 A099666 A099667

KEYWORD

base,nonn

AUTHOR

Labos Elemer, Nov 17 2004

STATUS

approved

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Last modified March 30 19:49 EDT 2020. Contains 333127 sequences. (Running on oeis4.)