A135441 Numbers k such that for any single digit d of k the d-th semiprime sp(k) is substring of k.

104, 410, 1004, 1014, 1040, 1041, 1044, 1104, 1410, 4010, 4100, 4101, 4104, 4110, 4410, 10004, 10014, 10040, 10041, 10044, 10104, 10114, 10140, 10141, 10144, 10145, 10400, 10401, 10404, 10410, 10411, 10414, 10440, 10441, 10444, 10514, 11004, 11014, 11040

Offset: 1

Author

Zak Seidov, Feb 17 2008

Keywords

• nonn
• base

Comments

sp(1..9)=4,6,9,10,14,15,21,22,25, with the convention that sp(0)=1.

Links

• David Applegate, Table of n, a(n) for n = 1..300

Crossrefs

Cf. A134439, A134962, A135463.

Extensions

Corrected and extended by David Applegate, Feb 18 2008