A163401 Numbers m such that all 10*m+d_1, 100*m+d_2 and 1000*m+d_3 are composite, where d_i are any i-digit numbers of A136333.

487856, 694103, 771084, 836254, 1051886, 1119347, 1122734, 1157014, 1181077, 1591742, 1638820, 1646819, 1820743, 1921148, 1945355, 2001782, 2026571

Offset

1,1

Comments

A subsequence A163398 satisfying an additional requirement on the 1000*m+d_3 compositions.

Links

Table of n, a(n) for n=1..17.

Example

m=487856 is in the sequence because 4878561, 4878563, 4878567, 4878569 from attachment of
d_1 = 1 to 9, and 48785611, 48785613, .., 48785697, 48785699 from attachment of
d_2 = 11 to 99, and 487856111, 487856113,..., 487856997, 487856999 from
attachment of d_3=111 to 999 are all composite.

Crossrefs

Cf. A002808.

Sequence in context: A190387 A183695 A216070 * A022215 A335083 A252847

Adjacent sequences: A163398 A163399 A163400 * A163402 A163403 A163404

Keyword

nonn,base

Author

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

Extensions

13 more terms from R. J. Mathar, Aug 07 2009

Status

approved