login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A235718 Squares which have one or more occurrences of exactly three different digits. 7

%I

%S 169,196,256,289,324,361,529,576,625,729,784,841,961,1156,1225,1521,

%T 1600,1681,2025,2116,2209,2500,3136,3364,3600,3844,3969,4225,4489,

%U 4624,4900,5625,5776,5929,6400,6561,6889,7225,8100,8281,8464,8836,9409,10201,10404

%N Squares which have one or more occurrences of exactly three different digits.

%C The first term having a repeated digit is 1156.

%H Giovanni Resta, <a href="/A235718/b235718.txt">Table of n, a(n) for n = 1..12299</a> (terms < 10^36, first 600 terms from Colin Barker)

%F a(n) = A054031(n)^2.

%e 5929 is in the sequence because 5929 = 77^2 and 5929 contains exactly three different digits: 2, 5 and 9.

%o (PARI) s=[]; for(n=1, 200, if(#vecsort(eval(Vec(Str(n^2))),,8)==3, s=concat(s, n^2))); s

%Y Cf. A235717, A235719-A235724, A225218.

%K nonn,base

%O 1,1

%A _Colin Barker_, Jan 15 2014

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 24 08:30 EDT 2021. Contains 345416 sequences. (Running on oeis4.)