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A259300
Near-repunits (ordered lexicographically).
1
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
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
KEYWORD
base,nonn,easy
AUTHOR
Robert G. Wilson v, Jun 23 2015
STATUS
approved