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A286300
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Square root of smallest square formed from n by incorporating all the digits of n in a new decimal number.
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1
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1, 5, 6, 2, 5, 4, 24, 9, 3, 10, 11, 11, 19, 12, 34, 4, 42, 9, 13, 32, 11, 15, 18, 18, 5, 16, 27, 17, 17, 48, 19, 18, 56, 18, 55, 6, 61, 59, 37, 20, 12, 18, 18, 12, 65, 8, 28, 22, 7, 45, 34, 15, 55, 65, 75, 16, 24, 72, 23, 40, 13, 16, 19, 8, 16, 26, 24, 41, 13
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OFFSET
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1,2
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COMMENTS
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Square root of less restrictive version of A091873: a(n) <= A091873(n).
First difference between a(n) and A091873(n) is for n=13. a(13) = sqrt(361) = 19, while A091873(13) = sqrt(1369) = 37.
If n is square then a(n) = sqrt(n).
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LINKS
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EXAMPLE
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a(4) = 2 since 4 = 2^2.
Table of the first 20 terms of related sequences:
1: 1 1 1 1
2: 25 5 25 5
3: 36 6 36 6
4: 4 2 4 2
5: 25 5 25 5
6: 16 4 16 4
7: 576 24 576 24
8: 81 9 81 9
9: 9 3 9 3
10: 100 10 100 10
11: 121 11 121 11
12: 121 11 121 11
13: 1369 37 361 19
14: 144 12 144 12
15: 1156 34 1156 34
16: 16 4 16 4
17: 1764 42 1764 42
18: 1089 33 81 9
19: 169 13 169 13
20: 2025 45 1024 32
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MATHEMATICA
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Table[If[IntegerQ@ Sqrt@ n, Sqrt@ n, k = Floor@ Sqrt@ n; Function[t, While[Function[w, Times @@ Boole@ Map[w[[#1]] >= #2 & @@ # &, #] < 1]@ DigitCount[k^2] &@ Apply[Join, Map[Lookup[t, #] /. d_ /; IntegerQ@ d :> If[d > 0, {d, #}, {10, #}] &, Keys@ t]], k++]]@ KeyDrop[PositionIndex@ DigitCount@ n, 0]; k], {n, 69}] (* Michael De Vlieger, May 05 2017, Version 10.1 *)
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CROSSREFS
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KEYWORD
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nonn,base,easy
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AUTHOR
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STATUS
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approved
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