A393902 Numbers k such that the digit reversals of k, when written in all bases 2 to 10, are less than k.

1080, 1800, 1801, 2160, 2322, 2520, 3360, 3690, 3780, 3990, 4320, 5040, 5160, 5440, 5600, 5761, 5880, 6000, 6160, 6216, 6225, 6280, 6440, 6840, 7056, 7065, 7560, 7632, 7696, 8136, 8352, 8640, 8856, 9360, 9432, 9576, 9810, 9936, 10080, 10440, 11160, 11880, 11970

Offset

1,1

Links

Scott R. Shannon, Table of n, a(n) for n = 1..10000

Example

1080 is a term as 1080 = 1080_10 = 1430_9 = 2070_8 = 3102_7 = 5000_6 = 13310_5 = 100320_4 = 1111000_3 = 10000111000_2 whose digital reversals are 801_10 = 801, 341_9 = 280, 702_8 = 450, 2013_7 = 696, 5_6 = 5, 1331_5 = 216, 23001_4 = 705, 1111_3 = 40, 11100001_2 = 225, all of which are less than 1080.

Mathematica

q[k_]:=AllTrue[IntegerReverse[k, Range[2, 10]], #<k&]; Select[Range[11970], q] (* James C. McMahon, Mar 02 2026 *)

Crossrefs

Cf. A393903, A393720, A393721, A393717, A393718, A305989, A305877, A004086.

Sequence in context: A214621 A179688 A392693 * A380930 A159210 A250538

Adjacent sequences: A393899 A393900 A393901 * A393903 A393904 A393905

Keyword

nonn,base

Author

Scott R. Shannon, Mar 02 2026

Status

approved