A163398 Numbers m such that all numbers 10*m+(odd single-digit number) and 100*m+(any 2-digit, digits coprime to 10) are composite.

167, 176, 403, 513, 761, 935, 1037, 1218, 1307, 1559, 1865, 1932, 1995, 2057, 2123, 2255, 2288, 2340, 2414, 2852, 3152, 3483, 3581, 3734, 3914, 4136, 4169, 4226, 4238, 4265, 4373, 4390, 4433, 4436, 4443, 4460, 4466, 4482, 4631, 4706, 4806, 4842, 4850

Offset

1,1

Comments

The first requirement is that 10m+1, 10m+3, 10m+5, 10m+7 and 10m+9 are all composite; for 10*m+5 with the divisor 5 this is redundant. The second requirement is that 100*m plus any 2-digit number of A136333 is also composite.

Links

Table of n, a(n) for n=1..43.

Example

m=167 is in the sequence because 1671, 1673, 1677, 1679, 16711, 16713, 16717, 16719, 16731,
16733, 16737, 16739, 16771, 16773, 16777, 16779, 16791, 16793, 16797, 16799 are composites.

Crossrefs

Cf. A002808.

Sequence in context: A144929 A281934 A212325 * A273548 A273549 A299379

Adjacent sequences: A163395 A163396 A163397 * A163399 A163400 A163401

Keyword

nonn,base,less

Author

Vladislav-Stepan Malakhovsky and Juri-Stepan Gerasimov, Jul 26 2009

Extensions

Rephrased in terms of A136333 and extended by R. J. Mathar, Aug 02 2009

Status

approved