A018829 Numbers n such that n is a substring of its square in base 5 (written in base 10).

0, 1, 5, 14, 25, 38, 125, 349, 408, 543, 625, 3125, 4743, 5292, 10888, 12196, 13201, 15625, 25509, 26460, 36536, 43614, 55038, 57837, 78125, 136888, 207889, 219698, 234783, 390625, 445663, 1090347, 1098490, 1336564, 1437874, 1720752, 1915227

Offset: 1

Author

David W. Wilson

Keywords

• nonn
• base

Crossrefs

Cf. A018826 (base 2), A018827 (base 3), A018828 (base 4), A018830 (base 6), A018831 (base 7), A018832 (base 8), A018833 (base 9), A018834 (base 10).

Programs

Mathematica

Select[Range[0,2*10^6],SequenceCount[IntegerDigits[ #^2,5],IntegerDigits[ #,5]]>0&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Oct 04 2019 *)