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A053919 Squares composed of digits {2,3,5}. 2
25, 225, 55225, 235225, 3553225, 33235225, 252333225, 2523555225, 3325252225, 5232352225, 3235555525225, 232555332555225, 35232553232323225, 32355552523523552532225, 25532532332552235533223325522255225 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..15.

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

STATUS

approved

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Last modified August 13 18:03 EDT 2022. Contains 356107 sequences. (Running on oeis4.)