A133786 Numbers prime to 10, 10's digit is odd and 100's digit is odd.

111, 113, 117, 119, 131, 133, 137, 139, 151, 153, 157, 159, 171, 173, 177, 179, 191, 193, 197, 199, 311, 313, 317, 319, 331, 333, 337, 339, 351, 353, 357, 359, 371, 373, 377, 379, 391, 393, 397, 399, 511, 513, 517, 519, 531, 533, 537, 539, 551, 553, 557

Offset: 1

Author

Jonathan Vos Post, Jan 02 2008

Keywords

• easy
• nonn
• base

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A045798.

Programs

Maple

seq(seq(seq(seq(10^3*a+10^2*b+10*c+d, d=[1,3,7,9]),c=1..9,2),b=1..9,2),a=0..1); # Robert Israel, May 20 2019

Formula

a(n+20)=a(n)+200. - Robert Israel, May 20 2019