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A328687 a(n) is the number of decimals in sqrt(n) needed for all digits 0-9 to occur or -1 if n is a perfect square. 0
-1, 18, 27, -1, 36, 38, 44, 35, -1, 26, 16, 24, 14, 35, 18, -1, 19, 35, 24, 36, 27, 12, 26, 51, -1, 39, 16, 37, 26, 25, 16, 22, 23, 36, 19, -1, 25, 25, 25, 40, 57, 56, 24, 11, 24, 21, 23, 26, -1, 33, 47, 22, 40, 48, 22, 31, 31, 22, 29, 18, 16, 30, 26, -1, 24 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

All positive terms are >= 10.

LINKS

Table of n, a(n) for n=1..65.

EXAMPLE

The decimals for sqrt(2) are .414213562373095048|801688724... and 18 decimals are needed for all digits to occur so a(2) = 18.

The decimals for sqrt(143) are .9582607431|01398021... so a(143) = 10.

The largest term when n < 10^9 is a(232863046) = 229.

CROSSREFS

Sequence in context: A284493 A337523 A167336 * A003634 A338383 A338385

Adjacent sequences:  A328684 A328685 A328686 * A328688 A328689 A328690

KEYWORD

sign,base

AUTHOR

Lars Blomberg, Oct 25 2019

STATUS

approved

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Last modified June 18 17:32 EDT 2021. Contains 345120 sequences. (Running on oeis4.)