

A235717


Squares which have one or more occurrences of exactly two different digits.


10



16, 25, 36, 49, 64, 81, 100, 121, 144, 225, 400, 441, 484, 676, 900, 1444, 7744, 10000, 11881, 29929, 40000, 44944, 55225, 69696, 90000, 1000000, 4000000, 9000000, 9696996, 100000000, 400000000, 900000000, 6661661161, 10000000000, 40000000000, 90000000000
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OFFSET

1,1


COMMENTS

The first term having a repeated digit is 100.
This sequence is the same as A018885, except that A018885 has four additional leading terms.


LINKS

Table of n, a(n) for n=1..36.


FORMULA

a(n) = A016069(n)^2.


EXAMPLE

69696 is in the sequence because 69696 = 264^2 and 69696 contains exactly two different digits: 6 and 9.


PROG

(PARI) s=[]; for(n=1, 10000, if(#vecsort(eval(Vec(Str(n^2))), , 8)==2, s=concat(s, n^2))); s


CROSSREFS

Cf. A235718A235724, A225218.
Sequence in context: A001033 A100647 A245371 * A319388 A291334 A175689
Adjacent sequences: A235714 A235715 A235716 * A235718 A235719 A235720


KEYWORD

nonn,base


AUTHOR

Colin Barker, Jan 15 2014


STATUS

approved



