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 A268031 Primes with the property that deleting some two digits one at a time in unique order gives a prime (with an even number of digits) at each step, until the empty string is reached. 0
 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 1009, 1021, 1049, 1051, 1063, 1069, 1087, 1201, 1409, 1609, 1663, 1669, 1801, 2003, 2011, 2017, 2063, 2069, 2267, 2609, 2621, 2657, 2663, 2687, 2767, 2861, 3001, 3023 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Chris Caldwell, The Prime Glossary, Deletable prime EXAMPLE The prime 2657 is in the sequence because the set {57, 67, 65, 27, 25, 26} contains only one two-digit prime. The prime 1021 is in the sequence because the set {21, 1, 2, 11, 12, 10} contains only one prime with an even number of digits. The prime 1579 is not in the sequence because the set {79, 59, 57, 19, 17, 15} contains four two-digit primes. The number 2087 is not in the sequence because the set {87, 7, 8, 27, 28, 20} does not contain any prime with an even number of digits. CROSSREFS Cf. A080608, A188809. Sequence in context: A095862 A125845 A108871 * A167847 A135779 A135778 Adjacent sequences:  A268028 A268029 A268030 * A268032 A268033 A268034 KEYWORD nonn,base AUTHOR Arkadiusz Wesolowski, Jan 24 2016 STATUS approved

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Last modified January 16 21:37 EST 2019. Contains 319206 sequences. (Running on oeis4.)