A053919 Squares composed of digits {2,3,5}.

25, 225, 55225, 235225, 3553225, 33235225, 252333225, 2523555225, 3325252225, 5232352225, 3235555525225, 232555332555225, 35232553232323225, 32355552523523552532225, 25532532332552235533223325522255225, 332222523225232223533222222253253255253352335533253225

Offset

1,1

Links

Table of n, a(n) for n=1..16.

Patrick De Geest, Squares containing at most three distinct digits, Index entries for related sequences

Author?, Source(txt)

H. Mishima Squares consisted of 3 different digits

Formula

a(n) = A053918(n)^2.

Prog

(Python) # see link in A053918 for a faster version
from math import isqrt
def aupto(limit):
  alst, rootlimit = [], isqrt(limit)
  for k in range(1, rootlimit+1):
    if set(str(k*k)) <= set("235"): alst.append(k*k)
  return alst
print(aupto(4*10**12)) # Michael S. Branicky, May 15 2021

Crossrefs

Cf. A053918.

Sequence in context: A036509 A034981 A276240 * A053927 A081195 A221930

Adjacent sequences: A053916 A053917 A053918 * A053920 A053921 A053922

Keyword

nonn,base

Author

Patrick De Geest, Mar 15 2000

Extensions

More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 03 2005

One more term from Mishima's webpage added by Max Alekseyev, Jun 17 2011

a(16) from Zhao Hui Du, Feb 29 2024

Status

approved