A028910 Arrange digits of 2^n in descending order.

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

Alois P. Heinz, Table of n, a(n) for n = 0..3321

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

Adjacent sequences: A028907 A028908 A028909 * A028911 A028912 A028913

Keyword

nonn,base

Author

N. J. A. Sloane

Extensions

More terms from Patrick De Geest, Apr 15 1998

Status

approved