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A355063
Perfect powers whose digits are in nonincreasing order and do not include 0.
0
1, 4, 8, 9, 32, 64, 81, 441, 841, 961, 7744, 7776, 8874441, 9853321, 999887641
OFFSET
1,2
COMMENTS
a(16) > 10^45 if it exists. - Michael S. Branicky, Jun 19 2022
PROG
(Python)
from sympy import perfect_power as pp
from itertools import count, islice, combinations_with_replacement as mc
def agen():
yield 1
for d in count(1):
nd = (int("".join(m)) for m in mc("987654321", d))
yield from sorted(filter(pp, nd))
print(list(islice(agen(), 14))) # Michael S. Branicky, Jun 16 2022
(PARI) isok(m) = if (ispower(m), my(d=digits(m)); vecmin(d) && (d == vecsort(d, , 4))); \\ Michel Marcus, Jun 17 2022
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Jon E. Schoenfield, Jun 16 2022
STATUS
approved