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Search: a118767 -id:a118767
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a(n) = smallest number not occurring earlier having in decimal representation to its predecessor Levenshtein distance = 1; a(0)=0.
+10
14
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 19, 10, 11, 12, 13, 14, 15, 16, 17, 18, 28, 20, 21, 22, 23, 24, 25, 26, 27, 29, 39, 30, 31, 32, 33, 34, 35, 36, 37, 38, 48, 40, 41, 42, 43, 44, 45, 46, 47, 49, 59, 50, 51, 52, 53, 54, 55, 56, 57, 58, 68, 60, 61, 62, 63, 64, 65, 66, 67, 69, 79, 70, 71
OFFSET
0,3
COMMENTS
Permutation of the natural numbers; inverse: A118764; A118765(n)=a(a(n)); a(A118767(n))=A118767(n);
A118768(n) = a(n+1) - a(n);
MATHEMATICA
levenshtein[s_List, t_List] := Module[{d, n = Length@ s, m = Length@ t}, Which[s === t, 0, n == 0, m, m == 0, n, s != t, d = Table[0, {m + 1}, {n + 1}]; d[[1, Range[n + 1]]] = Range[0, n]; d[[Range[m + 1], 1]] = Range[0, m]; Do[ d[[j + 1, i + 1]] = Min[d[[j, i + 1]] + 1, d[[j + 1, i]] + 1, d[[j, i]] + If[ s[[i]] === t[[j]], 0, 1]], {j, m}, {i, n}]; d[[ -1, -1]] ]]; f[lst_] := Block[{k = 1, l = IntegerDigits[ lst[[-1]]]}, While[ MemberQ[lst, k] || levenshtein[l, IntegerDigits[k]] > 1, k++]; Append[lst, k]]; Nest[f, {0}, 100] (* Robert G. Wilson v, Sep 22 2016 *)
PROG
(Python)
from itertools import islice
from Levenshtein import distance as Ld
def agen(): # generator of terms
an, aset, mink = 0, {0}, 1
while True:
yield an
s, k = str(an), mink
while k in aset or Ld(s, str(k)) != 1: k += 1
an = k
aset.add(k)
while mink in aset: mink += 1
print(list(islice(agen(), 73))) # Michael S. Branicky, Dec 01 2023
CROSSREFS
Cf. A118757.
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, May 01 2006
STATUS
approved
Inverse of A118763.
+10
6
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 10, 21, 22, 23, 24, 25, 26, 27, 28, 20, 29, 31, 32, 33, 34, 35, 36, 37, 38, 39, 30, 41, 42, 43, 44, 45, 46, 47, 48, 40, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 50, 61, 62, 63, 64, 65, 66, 67, 68, 60, 69, 71, 72, 73
OFFSET
0,3
COMMENTS
Permutation of the natural numbers with fixed points A118767: a(A118767(n))=A118767(n);
A118766(n) = a(a(n)).
MATHEMATICA
(* first do Mmca in A118763, then *) Flatten@ Table[Position[s, n], {n, 0, 100}] - 1 (* Robert G. Wilson v, Sep 22 2016 *)
CROSSREFS
Cf. A118758.
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, May 01 2006
STATUS
approved
Fixed points of permutations A118757, A118758, A118759 and A118760.
+10
5
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 119, 138, 157, 176, 195, 310, 339, 358, 377, 396, 559, 578, 597, 779, 798, 999, 3130
OFFSET
1,3
COMMENTS
A118757(a(n)) = A118758(a(n)) = A118759(a(n)) = A118760(a(n)) = a(n);
a(n) = A024657(n-1) = A102491(n) for n<=50.
CROSSREFS
Cf. A118767.
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, May 01 2006
STATUS
approved

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