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A261449
Prime numbers whose decimal digits contain a total of two loops.
0
83, 109, 149, 181, 199, 269, 281, 283, 349, 383, 401, 419, 439, 443, 461, 463, 467, 479, 491, 509, 569, 587, 599, 601, 607, 619, 641, 643, 647, 659, 661, 691, 709, 769, 787, 811, 821, 823, 827, 853, 857, 877, 907, 919, 929, 941, 947, 967, 991, 997, 1019, 1039
OFFSET
1,1
COMMENTS
Of the digits, 0 through 9, {0, 4, 6, 9} have one loop, 8 has two loops, and all the rest have none. - Robert G. Wilson v, Aug 20 2015
EXAMPLE
83 is the first term of the sequence. The digit 8 contains two closed curves.
MATHEMATICA
Select[Prime@ Range@ 200, 2 == Total[{ 1, 0, 0, 0, 1, 0, 1, 0, 2, 1}[[1 + IntegerDigits@ #]]]&] (* Giovanni Resta, Aug 19 2015 *)
CROSSREFS
KEYWORD
nonn,less,easy,base
AUTHOR
Altug Alkan, Aug 19 2015
EXTENSIONS
More terms from Giovanni Resta, Aug 19 2015
STATUS
approved