A235717 Squares which have one or more occurrences of exactly two different digits.

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

Offset: 1

Author

Colin Barker, Jan 15 2014

Keywords

• nonn
• base

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.

Examples

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

Crossrefs

Cf. A235718-A235724, A225218.

Programs

PARI

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

Formula

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