A353080 Numbers whose squares have the first three digits the same as the next three digits.
1429, 1537, 1692, 1823, 2001, 2312, 2467, 2729, 2858, 3148, 3242, 3635, 3849, 4002, 4541, 4552, 5851, 6003, 6216, 6296, 6375, 7145, 7152, 7159, 7698, 8004, 9093, 9104, 9235, 9444, 10005, 10154, 12006, 12335, 13645, 14007, 14290, 14325, 15272, 15370, 16008, 16531
Offset: 1
Examples
1429^2 = 2042041 and 1537^2 = 2362369. Thus, 1429 and 1537 are both in this sequence.
Links
- Alois P. Heinz, Table of n, a(n) for n = 1..10000
Programs
-
Maple
q:= n-> (s-> is(s[1..3]=s[4..6]))(""||(n^2)): select(q, [$317..17000])[]; # Alois P. Heinz, Apr 22 2022 -
Mathematica
Select[Range[317, 20000], Take[IntegerDigits[#^2], {1, 3}] == Take[IntegerDigits[#^2], {4, 6}] &] -
Python
def ok(n): s = str(n**2); return len(s) > 5 and s[:3] == s[3:6] print([k for k in range(20000) if ok(k)]) # Michael S. Branicky, Apr 22 2022