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A045921 Primes with two alternating digits. 2
13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 131, 151, 191, 313, 353, 373, 757, 797, 919, 35353, 95959, 919191919, 979797979, 91919191919, 151515151515151, 737373737373737, 75757575757575757, 91919191919191919 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..72

MATHEMATICA

Sort[Select[Flatten[Select[FromDigits/@Table[PadRight[{}, n, #], {n, 21}], PrimeQ]&/@ Select[Sort[Flatten[Permutations/@Subsets[ Range[ 0, 9], {2}], 1]], OddQ[Last[#]]&]], #>9&]] (* Harvey P. Dale, May 25 2015 *)

CROSSREFS

Sequence in context: A008365 A132077 A235154 * A296520 A034845 A241059

Adjacent sequences:  A045918 A045919 A045920 * A045922 A045923 A045924

KEYWORD

nonn,base

AUTHOR

Erich Friedman

EXTENSIONS

Corrected and extended by Harvey P. Dale, May 25 2015

STATUS

approved

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Last modified April 5 20:09 EDT 2020. Contains 333260 sequences. (Running on oeis4.)