A259300 Near-repunits (ordered lexicographically).

101, 110, 112, 113, 114, 115, 116, 117, 118, 119, 121, 131, 141, 151, 161, 171, 181, 191, 211, 311, 411, 511, 611, 711, 811, 911, 1011, 1101, 1110, 1112, 1113, 1114, 1115, 1116, 1117, 1118, 1119, 1121, 1131, 1141, 1151, 1161, 1171, 1181, 1191, 1211, 1311, 1411, 1511, 1611, 1711, 1811, 1911, 2111, 3111, 4111, 5111, 6111, 7111, 8111, 9111

Offset

1,1

Comments

The repunits are in A002275; therefore, to be a near-repunit, x must have only one other digit besides one, and the ones must outnumber the other digit.

Number of terms < 10^k: 0, 0, 26, 35, 44, 53, 62, 71, 80, 89, ...; this is 9k-1 for k>2.

Links

Robert G. Wilson v, Table of n, a(n) for n = 1..10080

Mathematica

f[n_] := Block[{lst = {}, r = (10^(n-1) -1)/9}, Do[ AppendTo[lst, Select[ FromDigits[ Permutations[ Append[ IntegerDigits@ r, d]]], # > r &]], {d, {0, 2, 3, 4, 5, 6, 7, 8, 9}}]; Union@ Flatten@ lst]; f[1] = f[2] = {}; Array[f, 4] // Flatten

Crossrefs

Cf. A002275.

Sequence in context: A366106 A140799 A086918 * A025349 A025341 A290725

Adjacent sequences: A259297 A259298 A259299 * A259301 A259302 A259303

Keyword

base,nonn,easy

Author

Robert G. Wilson v, Jun 23 2015

Status

approved