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A108203
Numbers n put into lexicographical order which are the concatenation of k and the sum of the digits of k.
4
11, 22, 33, 44, 55, 66, 77, 88, 99, 101, 112, 123, 134, 145, 156, 167, 178, 189, 202, 213, 224, 235, 246, 257, 268, 279, 303, 314, 325, 336, 347, 358, 369, 404, 415, 426, 437, 448, 459, 505, 516, 527, 538, 549, 606, 617, 628, 639, 707, 718, 729, 808, 819, 909, 1001
OFFSET
1,1
EXAMPLE
1 --> 11, 2 --> 22, 3 --> 33, ..., 9 --> 99, 10 --> 101, 11 --> 112, 12 --> 123,
..., 18 --> 189, 19 --> 1910 (ouch!), 20 --> 202, 21 --> 213, ...
MATHEMATICA
f[n_] := FromDigits[ Join[ IntegerDigits[ n], IntegerDigits[Plus @@ IntegerDigits[ n]] ]]; t = {}; Do[t = Union[AppendTo[t, f[n]]], {n, 10^6}]
CROSSREFS
Cf. A062028, A064806. Equals A108773 sorted.
Sequence in context: A343444 A193772 A178359 * A308104 A108773 A282151
KEYWORD
base,nonn
AUTHOR
EXTENSIONS
a(55) from Rémy Sigrist, May 16 2019
STATUS
approved