A295015 Squares whose largest digit is 5.

25, 225, 1225, 1521, 2025, 2500, 3025, 4225, 5041, 11025, 12544, 13225, 21025, 22500, 24025, 34225, 35344, 42025, 44521, 52441, 55225, 112225, 122500, 133225, 135424, 150544, 151321, 152100, 202500, 212521, 235225, 245025, 250000, 251001, 252004, 255025, 302500

Offset: 1

Author

M. F. Hasler, Nov 12 2017

Keywords

• nonn
• base

Links

• Michael S. Branicky, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A295015 (square roots of the terms); A277946, A277947, A277948, A295016 .. A295019 (analog for digits 2 through 9); A295025 (analog for cubes).

Cf. A000290 (the squares).

Programs

Mathematica

Select[Range[600]^2,Max[IntegerDigits[#]]==5&] (* Harvey P. Dale, Aug 19 2022 *)

PARI

is_A295015(n)=issquare(n)&&n&&vecmax(digits(n))==5 \\ The "n&&" avoids an error message for n = 0.

Python

from math import isqrt
def aupto(limit):
  alst, rootlimit = [], isqrt(limit)
  for k in range(1, rootlimit+1):
    if max(str(k*k)) == "5": alst.append(k*k)
  return alst
print(aupto(302500)) # Michael S. Branicky, May 15 2021

Formula

a(n) = A295005(n)^2.