OFFSET
1,1
COMMENTS
Elements are squares of integers in (sqrt(71), sqrt(80)) * sqrt(10)^k without the leading 7 elements for nonnegative k. - David A. Corneth, May 20 2016
LINKS
Nathan Fox, Table of n, a(n) for n = 1..10000
EXAMPLE
84 is a member because 784 = 28^2 is a square.
0 is not a member because 70 is not a square.
MAPLE
t1:=[];
for k from 1 to 50000 do
if issqr(k+7*10^length(k)) then t1:=[op(t1), k]; fi;
od;
t1;
MATHEMATICA
Select[Range[35000], IntegerQ[Sqrt[7*10^IntegerLength[#]+#]]&] (* Harvey P. Dale, Feb 10 2019 *)
PROG
(Magma) [n: n in [1..20000 ] | IsSquare(Seqint(Intseq(n) cat Intseq(7)))]; // Marius A. Burtea, Mar 21 2019
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved