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A028910
Arrange digits of 2^n in descending order.
14
1, 2, 4, 8, 61, 32, 64, 821, 652, 521, 4210, 8420, 9640, 9821, 86431, 87632, 66553, 732110, 644221, 885422, 8765410, 9752210, 9444310, 8888630, 77766211, 55443332, 88766410, 877432211, 866554432, 987653210, 8774432110, 8876444321
OFFSET
0,2
LINKS
MAPLE
a:= n-> parse(cat(sort(convert(2^n, base, 10), `>`)[])):
seq(a(n), n=0..50); # Alois P. Heinz, Jan 21 2020
MATHEMATICA
FromDigits[Reverse[Sort[IntegerDigits[#]]]]&/@(2^Range[0, 40]) (* Harvey P. Dale, Mar 06 2020 *)
PROG
(Magma) [Seqint(Sort(Intseq(2^n))):n in [0..31]]; // Marius A. Burtea, Oct 06 2019
(Python)
def A028910(n):
return int(''.join(sorted(str(2**n), reverse=True))) # Chai Wah Wu, Feb 19 2021
CROSSREFS
The following are parallel families: A000079 (2^n), A004094 (2^n reversed), A028909 (2^n sorted up), A028910 (2^n sorted down), A036447 (double and reverse), A057615 (double and sort up), A263451 (double and sort down); A000244 (3^n), A004167 (3^n reversed), A321540 (3^n sorted up), A321539 (3^n sorted down), A163632 (triple and reverse), A321542 (triple and sort up), A321541 (triple and sort down).
Sequence in context: A094333 A018473 A004094 * A018482 A036447 A371966
KEYWORD
nonn,base
EXTENSIONS
More terms from Patrick De Geest, Apr 15 1998
STATUS
approved