A137056 Numbers k such that k and k^2 use only the digits 1, 4, 6 and 9.

1, 4, 14, 119, 4119

Offset

1,2

Comments

Generated with DrScheme.

From Pontus von Brömssen, May 01 2024: (Start)

a(6) > 10^43 (if it exists).

If k = x*10^m is a term where 1 <= x < 10 and k is not 1 or 119, then 1.1914114169419441614111944144941411111111191 < x < 20/3.

(End)

Links

Table of n, a(n) for n=1..5.

J. Wellons, Tables of Shared Digits [archived]

Example

4119^2 = 16966161.

Prog

(PARI) isokd(d) = #setintersect([0, 2, 3, 5, 7, 8], Set(d)) == 0;
isok(k) = isokd(digits(k)) && isokd(digits(k^2)); \\ Michel Marcus, Jun 24 2021

Crossrefs

Sequence in context: A065062 A240273 A137048 * A302021 A006824 A333730

Adjacent sequences: A137053 A137054 A137055 * A137057 A137058 A137059

Keyword

base,nonn,more

Author

Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008

Status

approved