login
A235718
Squares which have one or more occurrences of exactly three different digits.
7
169, 196, 256, 289, 324, 361, 529, 576, 625, 729, 784, 841, 961, 1156, 1225, 1521, 1600, 1681, 2025, 2116, 2209, 2500, 3136, 3364, 3600, 3844, 3969, 4225, 4489, 4624, 4900, 5625, 5776, 5929, 6400, 6561, 6889, 7225, 8100, 8281, 8464, 8836, 9409, 10201, 10404
OFFSET
1,1
COMMENTS
The first term having a repeated digit is 1156.
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..12299 (terms < 10^36, first 600 terms from Colin Barker)
FORMULA
a(n) = A054031(n)^2.
EXAMPLE
5929 is in the sequence because 5929 = 77^2 and 5929 contains exactly three different digits: 2, 5 and 9.
PROG
(PARI) s=[]; for(n=1, 200, if(#vecsort(eval(Vec(Str(n^2))), , 8)==3, s=concat(s, n^2))); s
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Colin Barker, Jan 15 2014
STATUS
approved