A018831 Numbers n such that n is a substring of its square in base 7 (written in base 10).

0, 1, 7, 30, 49, 285, 343, 911, 1900, 2208, 2401, 13962, 16807, 59763, 64098, 69128, 85880, 97734, 117649, 195032, 418341, 754422, 823543, 2162126, 2629229, 2790841, 3488518, 3842400, 4960401, 5764801, 7923812, 8559490, 15134882, 19765943, 31466333, 36415297

Offset

1,3

Links

Table of n, a(n) for n=1..36.

Mathematica

Select[Range[0, 10^7], StringContainsQ[IntegerString[#^2, 7], IntegerString[#, 7]] &] (* Paolo Xausa, Apr 05 2024 *)

Crossrefs

Cf. A018826 (base 2), A018827 (base 3), A018828 (base 4), A018829 (base 5), A018830 (base 6), A018832 (base 8), A018833 (base 9), A018834 (base 10).

Sequence in context: A339098 A210107 A266604 * A063128 A063148 A116283

Adjacent sequences: A018828 A018829 A018830 * A018832 A018833 A018834

Keyword

nonn,base

Author

David W. Wilson

Extensions

a(35)-a(36) from Pontus von Brömssen, Apr 04 2024

Status

approved