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A036342
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Prime concatenated analog clock numbers read clockwise.
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4
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2, 3, 5, 7, 11, 23, 67, 89, 4567, 23456789, 23456789101112123, 891011121234567891011, 23456789101112123456789101112123, 567891011121234567891011121234567891011, 121234567891011121234567891011121234567891011121, 91011121234567891011121234567891011121234567891011121234567
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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COMMENTS
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The hours 10, 11 and 12 are taken 'complete and unreversed'.
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LINKS
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PROG
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(Python)
import heapq
from sympy import isprime
from itertools import islice
def A036342_gen(): # generator of terms
h = [(i, i) for i in range(1, 13)]
while True:
v, last = heapq.heappop(h)
if isprime(v):
yield v
nxt = 1 if last == 12 else last+1
shift = 10 if nxt < 10 else 100
heapq.heappush(h, (v*shift+nxt, nxt))
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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