A262094 Orders m for which the only perfect digital invariants of order m are 0 and 1.

1, 2, 12, 15, 18, 22, 26, 28, 30, 40, 41, 48, 50, 52, 58, 80, 82, 88, 98, 103, 106, 130, 135, 136, 138, 139, 140, 142, 150, 152, 159, 164, 165, 166, 174, 184, 185, 186, 188, 191, 192, 200, 213, 219, 222, 223, 224, 228, 234, 241, 246, 254, 258, 270

Offset

1,2

Comments

a(1), a(2), ... are the indices m for which A255668(m)=2, also A003321(m)=0, also A046761(m)=1.

The values seem to appear in clusters.

Links

Table of n, a(n) for n=1..54.

Example

a(3)=12 because there's no solution to x=(x_{12}...x_1x_0)_{10} = x_{12}^{12}+...+x_1^{12}+x_0^{12} except x=0 and x=1.

Crossrefs

Cf. A003321, A046761, A255668.

Sequence in context: A166745 A395207 A352504 * A200183 A118516 A077103

Adjacent sequences: A262091 A262092 A262093 * A262095 A262096 A262097

Keyword

nonn,base,more

Author

Don Knuth, Sep 10 2015

Extensions

a(35)-a(54) from Zhao Hui Du, Apr 13 2026

Status

approved