This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A352721 #25 May 22 2022 14:21:56 %S A352721 0,1,8,64,1000,8000,64000,1000000,8000000,64000000,1000000000, %T A352721 8000000000,64000000000,1000000000000,8000000000000,64000000000000, %U A352721 1000000000000000,8000000000000000,64000000000000000,1000000000000000000,8000000000000000000,64000000000000000000 %N A352721 Perfect cubes whose decimal digits appear in nonincreasing order. %F A352721 a(n) = A004647(n-1)^3. %e A352721 64 is in the sequence because it is a perfect cube (64 = 4^3) whose digits appear in nonincreasing order. %t A352721 Select[Range[0, 4*10^6]^3, Max@ Differences[IntegerDigits[#]] <= 0 &] (* _Amiram Eldar_, Mar 30 2022 *) %o A352721 (PARI) ok(n) = digits(n) == vecsort(digits(n),,4) && ispower(n,3) %Y A352721 Cf. A004647, A028820, A028864, A234848, A273045. %Y A352721 Intersection of A000578 and A009996. %K A352721 nonn,base %O A352721 1,3 %A A352721 _Antonio Roldán_, Mar 30 2022