proposed

approved

editing

proposed

Numbers nk such that for any single digit d of n we see alsok the d-th semiprime sp(nk) asis substring of nk.

_Zak Seidov, _, Feb 17 2008

Corrected and extended by _David Applegate, _, Feb 18 2008

approved

editing

David Applegate, <a href="="/A135441/b135441.txt">Table of n, a(n) for n = 1..300</a>

nonn,base,new

David Applegate, <a href="http://www.research.att.com/~njas/sequences/b135441.txt">Table of n, a(n) for n = 1..300</a>

nonn,base,new

Numbers n such that for any single digit d of n we see also the d-th semiprime sp(n) as substring of n.

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

1,1

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

David Applegate, <a href="http://www.research.att.com/~njas/sequences/b135441.txt">Table of n, a(n) for n = 1..300</a>

Cf. A134439, A134962, A135463.

nonn,base

Zak Seidov, Feb 17 2008

Corrected and extended by David Applegate, Feb 18 2008

approved