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

Author

Altug Alkan, Aug 19 2015

Keywords

• nonn
• less
• easy
• base

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

Examples

			83 is the first term of the sequence. The digit 8 contains two closed curves.
		

Crossrefs

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

Programs

Mathematica

Select[Prime@ Range@ 200, 2 == Total[{ 1,0, 0,0, 1,0, 1,0, 2,1}[[1 + IntegerDigits@ #]]]&] (* Giovanni Resta, Aug 19 2015 *)

Extensions

More terms from Giovanni Resta, Aug 19 2015