

A062118


Numbers n such that n^2 has n as its middle digits.


3



1, 50, 60, 250, 3792, 7600, 376000, 495475, 625000, 971582, 66952741, 93760000, 177656344, 3199268655, 9062500000, 10937600000, 788138178328, 860628177919, 890625000000, 2291665833333, 2780225311054, 2890625000000, 71093760000000, 128906250000000
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OFFSET

1,2


COMMENTS

Some of the terms are automorphic numbers (A003226) multiplied by an appropriate power of 10. a(25) > 10^15.  Giovanni Resta, Jul 29 2013


REFERENCES

Computed by Robert Israel.


LINKS

Table of n, a(n) for n=1..24.


EXAMPLE

a(5)=3792 because 3792^2 = 14379264 has 3792 as its middle digits.


MATHEMATICA

Do[ If[ StringPosition[ ToString[n^2], ToString[n]] [[1, 1]] == (Ceiling[ Log[10, n^2] ]  Ceiling[ Log[10, n] ])/2 + 1, Print[n] ], {n, 1, 10^9} ]


CROSSREFS

n^2 is given in A062120.
Sequence in context: A046832 A046834 A046836 * A167329 A179796 A215468
Adjacent sequences: A062115 A062116 A062117 * A062119 A062120 A062121


KEYWORD

nonn,base,nice


AUTHOR

Brian Wallace (wallacebrianedward(AT)yahoo.co.uk), Jun 28 2001


EXTENSIONS

Corrected and extended by Robert G. Wilson v, Aug 08 2001
a(15)a(24) from Giovanni Resta, Jul 29 2013


STATUS

approved



