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A052033
Primes base 10 that are never primes in any smaller base b, 2<=b<10, expansions interpreted as decimal numbers.
21
263, 269, 347, 397, 431, 461, 479, 499, 569, 599, 607, 677, 683, 719, 769, 797, 821, 929, 941, 1019, 1031, 1049, 1051, 1061, 1069, 1103, 1181, 1223, 1229, 1237, 1297, 1307, 1367, 1399, 1409, 1439, 1453, 1487, 1489, 1523, 1553, 1559, 1571, 1619, 1637
OFFSET
1,1
MATHEMATICA
Select[Prime[Range@ 265], Count[PrimeQ /@ Table[FromDigits[IntegerDigits[#, i]], {i, 2, 9}], True] == 0 &] (* Michael De Vlieger, Mar 20 2015 after Harvey P. Dale at A052032 *)
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Dec 15 1999
STATUS
approved