A261449 Prime numbers whose decimal digits contain a total of two loops.

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

Links

Table of n, a(n) for n=1..52.

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

Cf. A001729, A190222, A001743, A001744, A001745, A249572.

Sequence in context: A031412 A033252 A347226 * A288880 A126117 A096279

Adjacent sequences: A261446 A261447 A261448 * A261450 A261451 A261452

Keyword

nonn,less,easy,base

Author

Altug Alkan, Aug 19 2015

Extensions

More terms from Giovanni Resta, Aug 19 2015

Status

approved