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A074841
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Square root of n contains n as a string of digits to the immediate right of the decimal point (excluding leading zeros).
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12
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8, 77, 5711, 9797, 77327, 997997, 8053139, 60755907, 62996069, 99979997, 9999799997, 71515443427, 76933604839, 93445113269, 999997999997
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listen;
history;
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internal format)
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OFFSET
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1,1
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COMMENTS
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All numbers of the form (10^n-3)*(10^n+1), n > 0, are members. - Robert G. Wilson v, Aug 02 2004
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LINKS
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EXAMPLE
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The square root of 77327 = 278.077327...
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MATHEMATICA
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f[n_] := Block[{l = Floor[ Log[10, n] + 1], rd = RealDigits[ Sqrt[n], 10, 24], id = IntegerDigits[n]}, rdd = Drop[ rd[[1]], rd[[2]]]; While[ rdd[[1]] == 0, rdd = Drop[rdd, 1]]; Take[rdd, l] == id]; Do[ If[ StringPosition[ ToString[ N[ Sqrt[n], 24]], ToString[n]] != {}, If[ f[n], Print[n]]], {n, 2, 6 10^8}] (* Robert G. Wilson v, Aug 02 2004 *)
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PROG
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(PARI)
/* Uses PARI functions provided in link
* Sample run uses a = [0, 12], b=10, p=2, direct=True */
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CROSSREFS
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KEYWORD
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nonn,base,hard
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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