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A352721
Perfect cubes whose decimal digits appear in nonincreasing order.
0
0, 1, 8, 64, 1000, 8000, 64000, 1000000, 8000000, 64000000, 1000000000, 8000000000, 64000000000, 1000000000000, 8000000000000, 64000000000000, 1000000000000000, 8000000000000000, 64000000000000000, 1000000000000000000, 8000000000000000000, 64000000000000000000
OFFSET
1,3
FORMULA
a(n) = A004647(n-1)^3.
EXAMPLE
64 is in the sequence because it is a perfect cube (64 = 4^3) whose digits appear in nonincreasing order.
MATHEMATICA
Select[Range[0, 4*10^6]^3, Max@ Differences[IntegerDigits[#]] <= 0 &] (* Amiram Eldar, Mar 30 2022 *)
PROG
(PARI) ok(n) = digits(n) == vecsort(digits(n), , 4) && ispower(n, 3)
CROSSREFS
Intersection of A000578 and A009996.
Sequence in context: A293144 A349266 A111984 * A278145 A287230 A376446
KEYWORD
nonn,base
AUTHOR
Antonio Roldán, Mar 30 2022
STATUS
approved