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A090933
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Primes such that most significant digit swapped with all other digits yields primes.
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0
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2, 3, 5, 7, 11, 13, 17, 31, 37, 71, 73, 79, 97, 101, 107, 113, 131, 149, 167, 179, 181, 191, 199, 311, 337, 373, 389, 701, 709, 727, 733, 739, 751, 757, 787, 797, 907, 919, 937, 941, 953, 991, 1009, 1013, 1031, 1049, 1051, 1091, 1123, 1181, 1319, 1321, 1381
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Appears to be denser than A090934, where the least significant digit is swapped.
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EXAMPLE
| 149 is a term as 149, 419 & 491 are all prime.
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MATHEMATICA
| fQ[n_] := Block[{a = c = IntegerDigits[n], b = {}, l = Floor[ Log[10, n] + 1]}, Do[ a = c; {a[[1]], a[[i]]} = {a[[i]], a [[1]]}; AppendTo[b, FromDigits[a]], {i, 1, l}]; Union[ PrimeQ[b]] == {True}]; Select[ Prime[ Range[ 270]], fQ[ # ] &] (from Ed Pegg Jr. (ed(AT)mathpuzzle.com), Jan 15 2004)
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CROSSREFS
| Cf. A090934.
Sequence in context: A061461 A069706 A007500 * A107845 A090934 A068652
Adjacent sequences: A090930 A090931 A090932 * A090934 A090935 A090936
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KEYWORD
| base,nonn
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AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Dec 29 2003
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EXTENSIONS
| Edited, corrected and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 15 2004
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