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A053919
Squares composed of digits {2,3,5}.
3
25, 225, 55225, 235225, 3553225, 33235225, 252333225, 2523555225, 3325252225, 5232352225, 3235555525225, 232555332555225, 35232553232323225, 32355552523523552532225, 25532532332552235533223325522255225, 332222523225232223533222222253253255253352335533253225
OFFSET
1,1
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
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